Hamid Pousti
email: hamid.pousti@monash.edu

Cathy Urquhart
email: c.urquhart@mmu.ac.uk

Henry Linger
email: henry.linger@monash.edu

Exploring the Role of Social Media in Chronic Care Management: A Sociomaterial Approach

Keywords: social media, community, sociomateriality

This paper examines how social media can support communities of patients with chronic illness and their care givers. This study is a qualitative case study and is informed by grounded theory. Sociomateriality is adopted as a theoretical lens to understand and explain the key findings. Our findings suggest that there is a dynamic relation between the contrary roles that social media in chronic care management and this is not only attributed to the functionalities of these technologies but to the attributes of patients and their states of health. We were also able to observe how these technologies are bounded up with human activities in the ways that separating them is not possible. What we learnt from our findings is that the ways patients and carers use of social media can change their perceptions about their conditions, and influence how they understand and approach the management process.

Introduction

This paper examines how social media can support communities of patients with chronic illness and their care givers. Chronic disease are long term universal disorders, characterized as complex and non-curable conditions with prolonged impacts on individuals and communities [START_REF] Lindholm | Does Chronic Illness Cause Adverse Social and Economic Consequences among Swedes?[END_REF]. It is argued that the complex process of chronic care management is challenging the wealth and functionalities of many individuals and communities by putting extra demands and pressure on the scarce healthcare and other communal resources [START_REF] Greenhalgh | Patient and Public Involvement in Chronic Illness: Beyond the Expert Patient[END_REF]. However, studies suggest that information and communication technology can alleviate the adverse impact of chronic disease by supporting many aspects of the management process and potentially improve its outcomes [START_REF] Greene | Online Social Networking by Patients with Diabetes: A Qualitative Evaluation of Communication with Facebook[END_REF][START_REF] Jennings | A Virtual Clinic for Diabetes Self-Management: Pilot Study[END_REF].

Recent studies show that there is a growing trend of using social media in the process of chronic care management [START_REF] Li | Improving Chronic Disease Self-Management through Social Networks[END_REF], to the extent that some researchers believe this trend is transforming the process from a clinical-based activities to a more self-managed and community dependent process [START_REF] Eysenbach | Medicine 2.0: Social Networking, Collaboration, Participation, Apomediation, and Openness[END_REF][START_REF] Ressler | Communicating the Experience of Chronic Pain and Illness through Blogging[END_REF].

While more empirical evidence is being reported regarding the different aspects of such a transformation [e.g. [START_REF] O'connor | Apomediation and Ancillary Care: Researchers' Responsibilities in Health-Related Online Communities[END_REF][START_REF] Stellefson | Web 2.0 Chronic Disease Self-Management for Older Adults: A Systematic Review[END_REF], there is still little known on how these new technologies can influence or support the communities of patients and carers that form around chronic care management. This is because social media afford new types of behaviors that were previously difficult or even impossible to achieve before these new technologies being adopted by patients and carers [START_REF] Majchrzak | The Contradictory Influence of Social Media Affordances on Online Communal Knowledge Sharing[END_REF][START_REF] Merolli | Health Outcomes and Related Effects of Using Social Media in Chronic Disease Management: A Literature Review and Analysis Of Affordances[END_REF].

The lack of solid scholarly knowledge to explain the empirical patterns of use of social media in healthcare activities, calls for a deeper understanding of how social media can support patients and carers who take parts of the management process online. Further, there is a need to explore how the online activities that occur through social media can influence the offline process of the chronic care management and its outcomes.

In light of these motivations, the purpose of this study is to explore and unpack the potential role of social media in supporting community of patients and carers involved in chronic care management. It also aims to deepen our understanding of how such roles may arise from users' perceptions about the affordances and constraints of social media. As such, the question this study aims to answer is:

What roles can social media play in supporting chronic care management, and how the characteristics of social media influence such supporting roles?

This study is a qualitative case study [START_REF] Flyvbjerg | Case Study[END_REF][START_REF] Walsham | Interpretive Case Studies in IS Research: Nature and Method[END_REF], and is informed by grounded theory as its method of exploration and analysis [START_REF] Glaser | The Discovery of Grounded Theory; Strategies for Qualitative Research[END_REF]. Sociomateriality is adopted as a theoretical lens to understand and explain the key findings of this study [START_REF] Orlikowski | Sociomateriality: Challenging the Separation of Technology, Work and Organization[END_REF]. By offering a relational perspective, this theoretical lens enables this study to highlight the unique and distinctive roles and capabilities of social media in chronic care management that exist beyond the material features of these technologies and the agency of their users, alone.

The paper proceeds as follows. The next section gives an overview of the wide range of literature on the use of social media in healthcare settings. We then discuss the sociomaterial lens used for this study in section 3. In section 4, we explain our methodology, including the grounded theory approach used in the study. Section 5 contains our findings about the role of social media in chronic care management. In Section 6, we engage our findings with the existing literature and our theoretical lens for the purposes of a discussion. Our final section comes to some conclusions about the role of social media in chronic healthcare management.

Literature Review

Literature about the application of social media in healthcare highlights the significance of these technologies in creating new opportunities for interactions and conversations between people who are involved in healthcare activities [START_REF] Marriott | Using Health Information Technology to Engage Communities in Health, Education, and Research[END_REF]. In particular, the literature points to the promising potential of social media in chronic care management, as well as the ways these technologies may challenges the process [START_REF] Lorig | The South Australia Health Chronic Disease Self-Management Internet Trial[END_REF]. Recently, there has been also a growing body of literature that highlights the means by which social media is transforming the process of chronic care management from a more clinical practice to a more community-based activity [START_REF] Eysenbach | Medicine 2.0: Social Networking, Collaboration, Participation, Apomediation, and Openness[END_REF][START_REF] O'connor | Apomediation and Ancillary Care: Researchers' Responsibilities in Health-Related Online Communities[END_REF].

In identifying the influence of social media in chronic care management, some researchers [e.g. 17] focus on social networking sites to highlight how these type of social media platforms can assist patients and caregivers to make better informed decisions and improve the quality of their lives. Wicks et al. [START_REF] Wicks | Sharing Health Data for Better Outcomes on PatientsLikeMe[END_REF] also highlight how Facebook, and other social networking communities can be built around data-sharing platforms, where patients share different types of information about their medical and social conditions.

The role of social media in facilitating the interaction between practitioners and patients is also highlighted in some of the studies that are concerned with chronic care management. For example a study by Jain [START_REF] Jain | Practicing Medicine in the Age of Facebook[END_REF] highlights how social networking sites are used by general practitioners who deliberately decided to become friends or connect with their patients to engage patients and also become more approachable. However, Keckley and Hoffmann [START_REF] Keckley | Social Networks in Health Care: Communication, Collaboration and Insights[END_REF] suggest that there is a complexity around this type of interaction and they cast doubts on the effectiveness of such approaches.

Stellefson et al. [START_REF] Stellefson | Web 2.0 Chronic Disease Self-Management for Older Adults: A Systematic Review[END_REF] present an analytical comparison between the traditional methods of providing health related information to patients with chronic disease, and the new trend of using social media. They argue that in the traditional methods of information provision, public health experts were providing chronic disease information in static form through Web 1.0, which primarily make written and audio materials available online. However, the rapid growth in adoption of social media has provided opportunities for participatory Internet interventions, to help individuals with chronic diseases become actively engaged in their own health care and become both the producers and consumers of information they need [START_REF] Murray | Interactive Health Communication Applications for People with Chronic Disease[END_REF][START_REF] Samoocha | Effectiveness of Web-Based Interventions on Patient Empowerment: A Systematic Review and Meta-Analysis[END_REF].

More studies also highlight other aspects of chronic care management that could be influenced by the use of social media. For instance, Mo and Coulson [START_REF] Mo | Empowering Processes in Online Support Groups among People Living With HIV/Aids: A Comparative Analysis of 'Lurkers' and 'Posters[END_REF] shows how social media can empower patients to become more active participants in the management of their conditions. Setoyama et al. [START_REF] Setoyama | Benefits of Peer Support in Online Japanese Breast Cancer Communities: Differences between Lurkers and Posters[END_REF] highlight the supporting role of social media facilitating the formation of online support groups, and Hara and Hew [START_REF] Hara | Knowledge-Sharing in an Online Community of Health-Care Professionals[END_REF] shows how these technologies support information and knowledge sharing process.

Most of these studies examine or measure the influence of social media on the outcome of chronic care management [START_REF] Nordfeldt | Patient and Parent Views on a Web 2.0 Diabetes Portal -The Management Tool, the Generator, and the Gatekeeper[END_REF]. Their approach is mostly to measure some medical or psychological parameter against certain features and functionalities that are designed into social media platforms [START_REF] Catherine | Designing and Evaluating a Web-Based Self-Management Site for Patients with Type 2 Diabetes -Systematic Website Development and Study Protocol[END_REF]. One area that these studies leave almost untouched is how the use of social media by patients and carers can change the perception of these groups about their health conditions and how that in turn would influence the ways they use social media. This calls for further investigation on the relation between technological aspects of social media and the social and human aspects chronic care management.

In the field of IS, in the recent years, IS scholars have shown an increasing interest in studying social media [START_REF] Vaast | Grounded Theorizing for Electronically Mediated Social Contexts[END_REF]. The importance of social media, and the significance of studying them as new technological innovations, have been widely discussed by IS scholars. The topic has been approached from variety of perspectives, including affordances of social media [e.g. [START_REF] Majchrzak | The Contradictory Influence of Social Media Affordances on Online Communal Knowledge Sharing[END_REF][START_REF] Treem | Social Media Use in Organizations: Exploring the Affordances of Visibility, Editability, Persistence, and Association[END_REF], their implications for virtual teams and communities [e.g. 89], their operational implications for organisations [e.g. 20], and their implications for social change [e.g. 5].

However, as Fichman et al. [START_REF] Fichman | The Role of Information Systems in Healthcare: Current Research and Future Trends[END_REF] argue, there is a need for more research from the IS community into the opportunities and challenges that social media can offer in the area of health IT issues. Agarwal et al. [START_REF] Agarwal | Research Commentary -The Digital Transformation of Healthcare: Current Status and the Road Ahead[END_REF] contend that the importance of technologies such as social media in healthcare is increasing, as these technologies are playing more influential roles in making healthcare services more affordable and more reachable. They argue that the significant role of IT in modern healthcare warrants more attention from IS researchers, especially in the areas that pertain to the expansion of online health communities.

Theoretical Lens

Sociomateriality is a theoretical framework that conceptualizes the social world through the relations between material agency of artifacts and the social agency of human [START_REF] Orlikowski | Sociomateriality: Challenging the Separation of Technology, Work and Organization[END_REF].

The sociomaterial perspective attempts to explain the social world as the enactment of meanings and materiality in everyday practices [START_REF] Orlikowski | The Sociomateriality of Organisational Life: Considering Technology in Management Research[END_REF]. In doing so, this perspective focuses on the performativity of a 'social object' -the term that what was initially coined by Berger and Luckmann [START_REF] Berger | The Social Construction of Reality: A Treatise in the Sociology of Knowledge[END_REF] -and its relation to its material features [START_REF] Zammuto | Information Technology and the Changing Fabric of Organization[END_REF]; rather than representing this object through language and numbers [START_REF] Barad | Posthumanist Performativity: Toward an Understanding of How Matter Comes to Matter[END_REF]. Agency is at the heart of sociomateriality. However, this view makes a distinctive move away from seeing agencies of both people and artifacts, as primarily independent and self-contained entities that influence each other, either through impacts (deterministic approach) or interactions (constructivist approach) [START_REF] Barley | What Can We Learn from the History of Technology[END_REF]. Instead, the focus is on agencies that have so thoroughly saturated each other in a way that boundaries between them are dissolved.

In this perspective materiality refers to the constituent features of a technological artifact that are available to all users in the same way [START_REF] Leonardi | Materiality, Sociomateriality, and Socio-Technical Systems: What Do These Terms Mean? How Are They Related? Do We Need Them?[END_REF]. However, as Majchrzak and Markus [START_REF] Majchrzak | Technology Affordances and Constraints Theory of Management Information Systems[END_REF] put, because people come to materiality with diverse goals and perceptions, an artifact can afford distinct possibilities or limitations for particular actions. This because the material out of which an object is made can provide multiple affordances and it is possible that one object can produce multiple outcomes [START_REF] Treem | Social Media Use in Organizations: Exploring the Affordances of Visibility, Editability, Persistence, and Association[END_REF]. Therefore, although materiality exists independent of people, but affordances do not.

From the sociomaterial perspective, the affordances of a technology are a set of potential possibilities that emerges through interactions between people and technology in practice, rather than as properties of either people or technology [START_REF] Hutchby | Technologies, Texts and Affordances[END_REF]. In other words, affordances depend not only on the material and functionalities that characterize an artifact, also on the expertise, processes, and people's understandings of what the artifact can afford.

Looking at social media artifacts through the lens of affordances provides several advantages. The main advantage, according to Treem and Leonardi [START_REF] Treem | Social Media Use in Organizations: Exploring the Affordances of Visibility, Editability, Persistence, and Association[END_REF], is that focus-ing on the entangled relationship between users and the material features of social media enables researchers to avoid privileging social determinism in explaining the patterns of social media use by users and ignoring the properties of the technology itself. The implication of this perspective for research is that the researchers need to base their analysis on the entangled and symbiotic relationships between the actions to be taken in a specific context and the capabilities of these technologies [START_REF] Majchrzak | The Contradictory Influence of Social Media Affordances on Online Communal Knowledge Sharing[END_REF].

Methodology

This study takes a qualitative case study approach [START_REF] Flyvbjerg | Case Study[END_REF]. Taking a qualitative approach was essential, as gaining an understanding of the role of social media in chronic care management and how these technologies can influence the dynamics of this process are deeply embedded in the actors' subjective understanding of the applications and roles of these technologies in chronic care management [START_REF] Myers | Qualitative Research in Information Systems[END_REF]. Data collection and data analysis of the study was informed by grounded theory [START_REF] Glaser | The Discovery of Grounded Theory; Strategies for Qualitative Research[END_REF][START_REF] Urquhart | Grounded Theory for Qualitative Research: A Practical Guide[END_REF]. The choice of grounded theory approach was entirely appropriate because very limited theoretical studies exist in this area and further exploration was essential [START_REF] Orlikowski | CASE Tools as Organizational Changes: Investigating Incremental and Radical Changes in System Development[END_REF]. The use of grounded theory as powerful exploratory approach was fruitful. Its flexible coding process enabled the investigation to focus on the contextual elements of the use of social media and unpack the underlying assumptions that would inform the actions and decisions of the key players in using these technologies for the management purposes.

While grounded theory provided this study with unique capabilities, we acknowledge that the findings of studies that are based on grounded theory can be very detailed and context bounded [START_REF] Layder | Sociological Practice: Linking Theory and Social Research[END_REF][START_REF] Urquhart | Putting the 'Theory' Back into Grounded Theory: Guidelines for Grounded Theory Studies in Information Systems[END_REF]. To address this concern, we concur with Orlikowski [START_REF] Orlikowski | CASE Tools as Organizational Changes: Investigating Incremental and Radical Changes in System Development[END_REF] and Walsham [START_REF] Walsham | Interpretive Case Studies in IS Research: Nature and Method[END_REF] and argue that the detailed findings of this study can be scaled up to generate more abstract and general explanations through the process of 'analytic generalization'. This means that the findings will be explained with insights from the extant literature, and in the light of the existing formal theory [START_REF] Urquhart | Putting the 'Theory' Back into Grounded Theory: Guidelines for Grounded Theory Studies in Information Systems[END_REF], in our case, sociomateriality.

Data Collection

Informed by the grounded theory method, the data collection of the study was designed in three stages of exploration of the subject matter, conceptualization of the phenomenon, and theorization [START_REF] Glaser | The Discovery of Grounded Theory; Strategies for Qualitative Research[END_REF]. Each stage was informed by the analysis of data from previous stages. At the exploratory stage, a focus group was conducted to explore the preliminary dimensions of the research problem, as well as the initial constructs that could inform the processes of constant comparison and theoretical sampling. The focus group was comprised of 10 participants, and all the participants were patients with arthritis and their carers. The session took two and half hours and was mediated by a professional mediator. The choice of arthritis was well justified as it is the most prevalent chronic disease in many developed countries [START_REF] Pink | 10 Year Book Australia[END_REF], and it is one of the most widespread chronic conditions around the world [START_REF] Alwan | Noncommunicable Diseases Country Profiles 2011[END_REF].

This stage revealed a number of key findings. First, it revealed the preliminary concepts related to role of social media in chronic care management. Second, it showed that although social media have promising potential for supporting chronic care management, there are a number of areas that were marked by significant uncertainties around social media use. Third, it suggested that many of the characteristics and applications of social media mentioned by the participants were related to or influenced by the material aspects of social media. The latter findings suggested, in Strauss's [START_REF] Strauss | Qualitative Analysis for Social Scientists[END_REF] language, that sociomateriality is a proper theoretical lens 'to grapple' with in order to explain the phenomenon under investigation.

Followed by the focus group, data was collected from social media sources, and complemented with semi-structured interviews. The initial concepts that emerged through the analysis of the focus group guided the process of collection, coding, and analysis of the data that came from social media resources. Major data came from variety of online patient forums and other social media platforms such as Facebook and Twitter. Forums used for this study were open to the public and researchers and were sponsored and maintained by health authorities, support organizations, and universities. The stories posted on the forums came from participants with different backgrounds and were generally from patients and carers, however, patients' family members, doctors, and other health professionals were also active members in those forums.

Forums were categorized into 17 categories based on the disease type they were representing. From the 17 different categories, the top five categories that represented the most prevalent chronic disease [START_REF] Pink | 10 Year Book Australia[END_REF] were chosen and forums with the highest volumes of posts were selected for the study. We observed that there was a correlation between the prevalence of a disease and the volume of interactions in forums. The collected data were examined through the process of constant comparison. This process enabled us to sharpen our thinking about the emerging concepts by writing theoretical memos, and enrich our understandings of their complexities.

For the purpose of theoretical sampling, a set of keywords (e.g. Facebook, forum, or online) that could help to identify messages and stories that were pointing to the use of social media were used. The result returned with 633 stories, mainly from people who were involved in the management of arthritis, diabetes, autism, asthma, and breast cancer. The 633 stories/messages were reviewed and 223 of them identified as relevant items based on the activity they represented (i.e. use of social media), the purpose of the activities (i.e. chronic care management), and the relevancy of the stories to the research question.

This stage of data collection spanned over a three months period, followed by interviews with some of the key participants in the forums. In total, nine semi-structured interviews were conducted for the deeper investigation of the emerging themes and for the purpose of reaching more theoretical saturation. The complementary sources of data provided valuable insight into the practices of social media by patients and carers, and also assisted in reaching theoretical saturation. In general, the iterative process of coding and analysis through constant comparison enabled the study to search out for contrasts and negative evidence while becoming sensitive to any new emerging concepts with possible alternative explanations [START_REF] Eisenhardt | Building Theories from Case Study Research[END_REF]. Table 1 presents detailed information about the data sources used in this study.

It is noteworthy that the use of social media resources provided this study with unique possibilities. For example, with regard to the analytical processes of coding, social media resources provided interesting benefits to this study by making it more convenient to collect new data, deeper exploration of the dimensions of the phenomenon, and to better contrast the findings with the previous observations within the study.

Data Analysis

Informed by the grounded theory, a rigorous Glaserian [START_REF] Glaser | Theoretical Sensitivity: Advances in the Methodology of Grounded Theory[END_REF] approach to coding was taken in this study. Therefore, coding took place through three stages of open, selective, and theoretical coding. The approach enabled to explore the major constructs and their dimensions pertaining to the use of social media in chronic care management. The coding approach also helped the researcher to ensure that theoretical saturation of the emergent categories was reached.

The data analysis proceeded with close reading and coding of the stories and messages extracted from the online forums, as well as the transcripts of the focus group and interviews. Particular attention was given to the perspectives of the patients and carers, as the major actors, in order to understand how and why they would use, or avoid using, forums or other social media platforms for managing their conditions. Figure 1 presents an overview of the analytical development of the emerged concepts. This section presents the findings as they were built up in the coding process. We present five categories that contribute to the theme of Role of Social Media: Building sense of community, Emotional support, Empowerment, Use of information, and Barriers. The composition of the theme is shown in the Figure 2. We also provide a chain of evidence for each category, so readers can see sample quotes for each category and the basis of that category in open coding.

Building Sense of Community

This selective code illustrates the means that social media can supports the creation of a sense of community as the patients and carers interact with each other. It shows how social media can help to bridge some of the social gaps that may result from issues such as differences in age, gender, or health conditions. This category shows social media supports the creation of a sense of community in chronic care management by building rapport among patients and carers (e.g. connecting people with different languages, or connecting people with different life experiences), supporting diversity (e.g. connecting people with different cultural backgrounds or in different age groups), facilitating peer and social support (e.g. supports social networks), facilitating learning (e.g. sharing experiences ), and supporting communication (e.g. supporting multiple channels and methods of communication)

Emotional Support

This selective code represents how the use of social media can assist patients and carers to get emotional support as they engage in the process of chronic care management. Management of chronic disease is usually with many uncertainties and surprises, creating many emotional difficulties for patients and care givers and therefore, in long term, getting emotional support becomes an important aspect of chronic care management [START_REF] Han | Breast Cancer and Problems with Medical Interactions: Relationships with Traumatic Stress, Emotional Self-Efficacy, and Social Support[END_REF]. In the light of this important aspect of the management process, the findings of this study revealed that social media can provide emotional support to the patients, carers, and their families by being a source of emotional comfort (e.g. helps to show sympathy or showing patients that they are not the only ones who have health problems), and by giving them access to the resources or interactions that can help them to raise their hopes for a better future (e.g. supports sharing positive experiences, or spreading encouraging words).

Empowerment

Traditionally chronic care management is a paternalistic process where the power of decision making and directing the management process mainly rest in the hands of practitioners [START_REF] Beisecker | Patient Power in Doctor-Patient Communication: What Do We Know?[END_REF][START_REF] Forster | Voice or Choice? Patient and Public Involvement in the National Health Service in England under New Labour[END_REF]. The finding of this study disclosed that social media can change this balance of power by enabling the patients and carers to gain new capabilities to support the management process (e.g. overcoming communication barriers), giving them more control over the management affairs (e.g. helps patients to become proactive), and equip them with resources (e.g. knowledge about existing local facilities) that enables them to negotiate healthcare and issues related to the management of their conditions (e.g. asking for better resources or alternative treatments).

Information Use

Chronic care management is an information intensive process [START_REF] Eysenbach | From Intermediation to Disintermediation and Apomediation: New Models for Consumers to Access and Assess the Credibility of Health Information in the Age of Web 2.0[END_REF]. This selective code represents how social media can support different information processes pertaining to chronic care management. The category of information use highlights the role that social media can play in facilitating the processes of information seeking (e.g. looking for information about their diseases or seeking information about the implications of the treatments they receive), information accessing (e.g. talking to people with similar condition), and information sharing (e.g. sharing their experiences with healthcare systems).

Barriers

The category of barriers illustrates the major uncertainties, concerns, and barriers against the adoption and use of social media in the management of chronic disease. While many studies suggest that social media have the potential to transcend the social and spatial barriers of chronic care management [START_REF] Barak | Fostering Empowerment in Online Support Groups[END_REF][START_REF] Van Uden-Kraan | Participation in Online Patient Support Groups Endorses Patients' Empowerment[END_REF]; the findings of this study suggests that this is not always the case. Therefore, it is important to understand what the barriers of using social media in chronic care management are and how they can debilitate the potential of social media for supporting chronic care management. Such an understanding can also assist to obviate these barriers or alleviate their impacts. Evidence indicated that there are two major groups of 'experienced' (e.g. source of bad news, or information quality can be poor) and 'perceived' (e.g. lack of confidence in using technology, or uncertainties around the legal issues of using social media) barriers to the use of social media in chronic care management. Table 2 provides sample quotes for each category, and shows the chain of evidence based in the open codes that make up each category.

Discussion

This section discusses the key findings of this study in the light of the existing literature, and also discusses these findings through the lens of affordances perspective.

Grounding the Key Findings Within the Extant Literature

In general, the findings of this study are congruent with earlier observations by Wellman et al. [START_REF] Wellman | Does the Internet Increase, Decrease, or Supplement Social Capital? Social Networks, Participation, and Community Commitment[END_REF], Ellison et al. [START_REF] Ellison | The Benefits of Facebook "Friends:" Social Capital and College Students' Use of Online Social Network Sites[END_REF] and Kane et al. [START_REF] Kane | Community relations 2.0[END_REF] that show the use of social media have become an important aspect of social life within communities and a growing resource for communication and interaction between their members. In particular, the findings from this study are consistent with the existing literature [e.g. [START_REF] Catherine | Designing and Evaluating a Web-Based Self-Management Site for Patients with Type 2 Diabetes -Systematic Website Development and Study Protocol[END_REF][START_REF] Korda | Harnessing Social Media for Health Promotion and Behavior Change[END_REF] suggesting that the use of social media can be beneficial to the chronic care management process, especially in providing emotional support to patients and carers and empowering them.

Emotional comfort Emotional support Sympathy

When I feel I want some sympathy and want to talk to somebody, I will be very tempted to go on the forum and talk to people there

Giving vent to feelings

Thanks for allowing me to vent. Today has been tough and very depressing

Sharing positive experiences

One of the best moments was when someone wrote how the person who couldn't get from the kitchen to the bathroom without a cane finally overcame it

Encouragement

There was a lot of patting on the back trying

Accessing new resources

Social media have opened up a whole lot of different avenues and new resources for us

Gaining new capabilities

Empowerment

Overcoming communication barriers

He is not able to speak anymore but still he can communicates with our children and friends through Facebook

Understanding of the conditions

I think I'm learning gradually that the OA symptoms deteriorate in the cold

Negotiation power

Negotiation for resources

You know, having to learn about the healthcare system, they develop some sense of what it is about and how to negotiate it

Knowledge acquisition

Knowledge is power really.

Being proactive I often look up for information there to find out what services are available in my area and where I need to go and ask for them

Gaining control

Prevent surprises

Nothing was anymore going to be a surprise or a shock for me about the procedure.

Choice I think when you have the right information you will feel easier with any decision that you make

Seeking information about diseases

Patients these days go online or use social media mainly for information seeking Seek Use of Information Seeking information for implications of treatments

I did talk about the possible drugs that I could use

Accessing relevant information

Some information that is not actually relevant to them Access Accessing information for decision making

It is a very compelling sort of way of using technology to help and support patients to make decision about what they want to do

Accessing to information for education

They can actually educate you by offering you relevant information

Sharing contents

Only [START_REF] Gibson | The Ecological Approach to Visual Perception[END_REF].

Same gender

We encourages young women with arthritis

Individuality

It's such an individual thing

Diversity Difference of geographical location

When you talk to different people, somebody in far north or in America

Spectrum of a disease type

We are all different because it is a spectrum

Social inclusion

For some isolated and lonely people, that it opens up a new world to them Social support

Social interaction

It is really good that he is able to stay in touch with other people

Social network You can have a network of people to support you

Sharing experiences People are talking about their own experiences

Learning Sharing knowledge I think most people that go on the forum are extremely knowledgeable and well prepared to teach you

Learning from feelings

I know exactly how your husband feels and I can actually tell you why

Communication with individuals

It gives you the opportunity to actually communicate with other patients

Communication Communication with the community

There's Facebook, there's Twitter and there are other amazing stuff out there have made it much easier for us to communicate with other people

Source of bad news You don't hear the good news on there. You just hear the bad news

Barrier experienced Barrier Depressive I stopped using the forum as it made me feel depressed

Information relevancy

The biggest challenge for us is the information we have on our Facebook are relevant

Lack of control over the content

The risk is that we will have little or no control over the content of Facebook

Reliability of sources

The forum will give you a lot, but again I find, you're better off talking to somebody who is expert rather than getting it from unreliable sources

Social isolation

My friends only communicate with me on Facebook

Social gap

People who use social media are in different social state from those who don't use technology

Confidentiality concerns

We are bound by laws that say we cannot talk to other people about our patients

Barrier Perceived Lack of regulations In terms of Facebook, there is no regulation for doing social media-based consultations

Age dependency Because arthritis patient are all older we couldn't communicate with them through Facebook

Computer literacy deficit

I don't understand what any of that is because I was a swimming instructor

Language barriers Something that we haven't done well at all in the past with our ethnics groups with none English background

Our findings show that an important aspect of using social media for chronic care management is that it can provide valuable emotional support to the patients and care givers. This finding is consistent with Frost and Massagli [START_REF] Frost | Social Uses Of Personal Health Information within Pa-tientsLikeMe, an Online Patient Community: What Can Happen When Patients Have Access to One Another's Data[END_REF], Nakayama et al. [START_REF] Nakayama | Potential Benefits and Harms of a Peer Support Social Network Service on the Internet for People with Depressive Tendencies: Qualitative Content Analysis and Social Network Analysis[END_REF], Setoyama et al. [START_REF] Setoyama | Benefits of Peer Support in Online Japanese Breast Cancer Communities: Differences between Lurkers and Posters[END_REF], suggesting that the use of different social media platforms can create positive emotional feelings for the patients and carers.

Emotional comfort found as a major dimension of emotional support. This finding is supported by Chung and Kim [START_REF] Chung | Blogging Activity Among Cancer Patients and Their Companions: Uses, Gratifications, and Predictors of Outcomes[END_REF] study of social media that shows the use of social media technologies such as blogs can generate a sense of emotional gratification and satisfaction among patients with chronic care. Vilhauer [START_REF] Vilhauer | Perceived benefits of online support groups for women with metastatic breast cancer[END_REF] also highlights instillation of hope, and catharsis, as two major benefits of social media mediated support groups. This is in accordant with the finding of this study suggesting raising hope as a major aspect of emotional support attainable through the use of social media.

The empowering role of social media has been widely discussed within the literature [START_REF] Mo | Empowering Processes in Online Support Groups among People Living With HIV/Aids: A Comparative Analysis of 'Lurkers' and 'Posters[END_REF][START_REF] Zhao | Identity Construction on Facebook: Digital Empowerment in Anchored Relationships[END_REF]. In the context of healthcare and especially chronic care management, the role of social media in empowering patients and carers is also highlighted frequently [e.g. [START_REF] Eysenbach | Medicine 2.0: Social Networking, Collaboration, Participation, Apomediation, and Openness[END_REF][START_REF] Lorig | The South Australia Health Chronic Disease Self-Management Internet Trial[END_REF]. In our findings we showed that one of the aspects of empowerment is the patients' feelings that they have more control over the management process. This finding is consistent with Van Uden-Kraan et al. [START_REF] Van Uden-Kraan | Empowering Processes and Outcomes of Participation in Online Support Groups for Patients with Breast Cancer, Arthritis, Or Fibromyalgia[END_REF] as their study of online support groups for patients with chronic illness reveal that sharing experiences through social media can empower patients by leading them to a feeling of regaining control over their personal lives and their future.

In our findings we also highlighted how social media can contribute into patients' and carers' empowerment through provisions of new capabilities such as accessing to new resources and expanding the scope and range of communication. These findings tally with the earlier research by Bartlett and Coulson [11] that shows the significant role of social media in expanding communication capabilities; also a study by O'Connor [START_REF] O'connor | Apomediation and the Significance of Online Social Networking[END_REF] highlights how social media technologies provides access to new resources that are beneficial to chronic care management.

We also explored social media support patients' and carers' empowerment by giving them more negotiation power. This aspect is not explicitly identified in the literature, but Van Uden-Kraan et al. [START_REF] Van Uden-Kraan | Empowering Processes and Outcomes of Participation in Online Support Groups for Patients with Breast Cancer, Arthritis, Or Fibromyalgia[END_REF] implicitly point to this aspect, by showing how the use of social media can help patients to feel confident in their relationships with their physicians. So, we believe our finding with regard to negotiation power extends the current literature about the empowering role of social media in healthcare.

The extant literature also supports the findings from this study that highlights the barriers of using social media for chronic care management. Studies by O'Keeffe and Clarke-Pearson [START_REF] O'keeffe | The Impact of Social Media on Children, Adolescents, and Families[END_REF] show that the use of social media can create distress and emotional discomfort for patients as they frequently read unpleasant news about their friends or other patients with similar conditions. Issues related to poor information quality and the reliability of information accessible through social media are also widely discussed by researchers [START_REF] Adams | Revisiting the Online Health Information Reliability Debate in the Wake of "Web 2.0": An Inter-Disciplinary Literature and Website Review[END_REF][START_REF] Marshall | Health Information: Does Quality Count For The Consumer? How Consumers Evaluate the Quality of Health Information Materials across a Variety of Media[END_REF]. Also, the different aspects of the social concerns related to the use of using social media by patients and carers are highlighted by Dutta-Bergman [START_REF] Dutta-Bergman | Trusted Online Sources of Health Information: Differences in Demographics, Health Beliefs, and Health-Information Orientation[END_REF].

Although not all the identified concerns about the legal dimensions of the barriers are discussed within the literature, confidentiality and privacy have been highlighted strongly within the literature [START_REF] Adams | Revisiting the Online Health Information Reliability Debate in the Wake of "Web 2.0": An Inter-Disciplinary Literature and Website Review[END_REF][START_REF] Antheunis | Patients' and Health Professionals' Use Of Social Media in Health Care: Motives, Barriers and Expectations[END_REF]. Evidence from literature also supports our findings regarding the lack of self-efficacy as a barrier of using social media for chronic care management. For example, findings from Nakayama et al. [START_REF] Nakayama | Potential Benefits and Harms of a Peer Support Social Network Service on the Internet for People with Depressive Tendencies: Qualitative Content Analysis and Social Network Analysis[END_REF] show that age and lack of confidence contributes in patients' avoidance to the use of social media. However, we suggest that our findings about the lack of computer literacy and language barriers can extend the literature in this area by adding new dimensions to these constructs (e.g. how the technological features of social media such as user interfaces couple up with users' health conditions and enact as a barrier) that were previously unexplored .

Viewing Our Findings Through the Lens of Sociomateriality

One way to explain the increasingly symbiotic relationship between social media and healthcare activities is through the lens of affordances. We adopt Majchrzak et al. [START_REF] Majchrzak | The Contradictory Influence of Social Media Affordances on Online Communal Knowledge Sharing[END_REF] definition of affordance and define technology affordances as the mutuality of actors' intentions and technology capabilities that provide the potential for particular actions.

In the light of this definition, a preliminary exploration of the use social media in chronic care management, shows that the ways the capabilities and limitations of these technologies are perceived by the patients and carers are highly influenced by the material aspects of social media platforms [START_REF] Pousti | Barriers of Using Social Media to Support Health-Related Decisions: A Sociomaterial Perspective[END_REF]. Also, findings from other studies [e.g. [START_REF] Merolli | Health Outcomes and Related Effects of Using Social Media in Chronic Disease Management: A Literature Review and Analysis Of Affordances[END_REF] show that many of the actors involved in chronic care management, specially patients and carers, often could enact new practices or achieve outcomes such as mobilizing social resources or fast and timely dissemination of sensitive information, that would not be possible without the use of social media and engaging with material features of these technologies. As such, informed by Gibson [START_REF] Gibson | The Ecological Approach to Visual Perception[END_REF] and Hutchby [START_REF] Hutchby | Technologies, Texts and Affordances[END_REF], we contend that our empirical findings lend themselves to analysis from an affordance perspective.

The relational concept of technology affordances suggests that social media have no inherent properties, boundaries or meaning but, as Barad [8] suggests, these technologies are bound up with the specific material-discursive practice that constitute their characteristics and affordances. As Zammuto et al. [START_REF] Zammuto | Information Technology and the Changing Fabric of Organization[END_REF] point out, based on the affordances perspective, technological possibilities of action are not given but they depend on the intent and perception of the actors enacting them.

Using an affordance lens suggests that although social media and the social features of chronic care management may exist independently of each other, their value for explaining the role of social media in the management process comes from how their agencies enact together.

This means, although social media and chronic care management process may have their own potentials and constraints, but as Zammuto et al. [START_REF] Zammuto | Information Technology and the Changing Fabric of Organization[END_REF] argue, an affordance perspective recognizes that a technological object has some recognized functionality but needs to be recognized as a social object. In other words, the influence of social media, as social objects -a term first coined by Barley [10] -on the management process cannot be separated from, for example, patients' status of health, their technology literacy, their communities, or any other social features pertaining to the management process. We therefore suggest a number of key affordances of social media in the context of chronic care management.

Emotional Support Affordance. The emotional support affordance is defined as a potential of social media to provide patients and carers with emotional support through emotional comfort and instillation of hopes. This affordance is enacted by the assemblage of material features of social media (e.g. hardware, software, or interfaces) and social features of chronic care management (e.g. friendship, or peer support).

Technologically, interactive environments such as online forums that enable synchronous and asynchronous interactions are needed to have the basic capabilities and elements of emotional support in place [START_REF] Adlassnig | Web-Based Resources for Peer Support -Opportunities and Challenges[END_REF]. In addition, databases, usually supplied through a service provider coupled with physical storage environments and other hardware are needed to store the history of interaction and give the capability of retrieving data to patients and carers [START_REF] Greene | Online Social Networking by Patients with Diabetes: A Qualitative Evaluation of Communication with Facebook[END_REF]. Further, algorithms are generally essential for authentication and protection of users' privacy and confidentiality [START_REF] Campisi | Privacy Protection in Social Media Networks a Dream That Can Come True?[END_REF] as many of the online participants seek support while staying anonymous [START_REF] Nakayama | Potential Benefits and Harms of a Peer Support Social Network Service on the Internet for People with Depressive Tendencies: Qualitative Content Analysis and Social Network Analysis[END_REF] or only interested to communicate with certain people [START_REF] Greene | Online Social Networking by Patients with Diabetes: A Qualitative Evaluation of Communication with Facebook[END_REF].

These technological features of social media need to be coupled with important social features of the management process to enact the affordance. These social features can include the type of the medium [START_REF] Hackworth | Health Care and Social Media: Building Relationships Via Social Networks[END_REF], the chronic disease types [START_REF] Merolli | Health Outcomes and Related Effects of Using Social Media in Chronic Disease Management: A Literature Review and Analysis Of Affordances[END_REF], the participants' demographics [START_REF] Correa | Who interacts on the Web?: The intersection of Users' Personality and Social Media Use[END_REF], the culture of the online forum [START_REF] Maloney-Krichmar | A Multilevel Analysis of Sociability, Usability, and Community Dynamics in an Online Health Community[END_REF], and the participants' attitudes and communication skills [START_REF] Moorhead | A New Dimension of Health Care: Systematic Review of the Uses, Benefits, and Limitations of Social Media for Health Communication[END_REF].

The emotional support affordance assists to understand and explain the role of social media in the outcome of chronic care management in ways that examining either social media or the management process separately does not. By investigating how social media can be used by different actors to provide emotional support to patients and carers, interdependencies and potential sources of support can be more easily identified. Also, features of social media that are more useful to the provision of such support and those that are less attractive can be more accurately pinpointed.

Empowerment Affordance. We define this affordance as the potential of social media in empowering patients and carers. The empowerment affordance is enacted through the relationship between the material features of social media (e.g. information representation, multiple format support, and information sharing spaces) and social features of chronic care management (e.g. knowledge acquisition, interaction with service providers, or decision making).

Technologically, several technological features are needed to enable this affordance. Technologies such as wikis, blogs, and online forums that enable users to produce, share, and access information are needed to support capabilities lead to patients and carers empowerment [START_REF] Samoocha | Effectiveness of Web-Based Interventions on Patient Empowerment: A Systematic Review and Meta-Analysis[END_REF][START_REF] Van Uden-Kraan | Participation in Online Patient Support Groups Endorses Patients' Empowerment[END_REF]. In addition, technologies that support the representation of information in different formats such as text, video, and audio are needed to help the patients and carers understand the different dimensions of an issue and acquire knowledge with more depth about the issues related to the management of their disease [START_REF] Zhao | Identity Construction on Facebook: Digital Empowerment in Anchored Relationships[END_REF]. These technical and material features of social media need to be conjoined with some of the significant aspects of chronic care management to make the empowerment affordance possible.

Several chronic care management features are needed as well to enable empowerment affordance. Features such as making decisions about different aspects of treatments [START_REF] Catherine | Designing and Evaluating a Web-Based Self-Management Site for Patients with Type 2 Diabetes -Systematic Website Development and Study Protocol[END_REF], negotiating work place related issue [START_REF] Koch | Bridging the Work/Social Divide: The Emotional Response to Organizational Social Networking Sites[END_REF], educating friends and families [START_REF] Marriott | Using Health Information Technology to Engage Communities in Health, Education, and Research[END_REF], and taking part in social activities [START_REF] Goldberg | Using an Internet Co-Management Module to Improve the Quality of Chronic Disease Care[END_REF], are just a few to name.

The affordance of empowerment assists to explain the role of social media in identifying the roles and relation between the actors involved in chronic care management. By examining how social media can give patients and carers a stronger voice and enable them playing a more central role in the management process, we can get a clearer understanding of how social media can support them to become more independent from healthcare services and engage in a more effective and fruitful self-management process. Also, by examining the empowerment affordance across different actors, it is possible to identify inter-power-relationships and inter-power-dependencies, which in turn could assist to get a deeper understanding of the technological and social features that, could more effectively support empowerment capabilities. Barriers Constraint. While the concept of affordance mainly represents potential capabilities for actions, as Hutchby [START_REF] Hutchby | Technologies, Texts and Affordances[END_REF] explains, an artifact's affordances and constraints are similar in nature. The notion of constraints emerges from an artifact's affordances and how people perceive an artifact can put constraints on their possibilities for action based on its affordances [START_REF] Majchrzak | Technology Affordances and Constraints Theory of Management Information Systems[END_REF]. Accordingly it is useful to consider how constraints might play out in using social media in chronic care management. Participants did independently identify constraints, which underlines why the theoretical lens is so helpful when considering this research problem.

The barriers constraint in our study is defined as the potential harm of using social media in chronic care management. This constraint is enacted through the dynamic relationship between the material agency of social media (e.g. security, confidentiality, and meta-information) and social agency (e.g. regulations, online relationships, information reliability) of chronic care management.

Several technological features of social media contribute in enactment of this constraint. Features like accessibility of depressive or concerning information [START_REF] Nakayama | Potential Benefits and Harms of a Peer Support Social Network Service on the Internet for People with Depressive Tendencies: Qualitative Content Analysis and Social Network Analysis[END_REF], poor filtering features [START_REF] Agichtein | Finding high-quality content in social media[END_REF], complex interfaces and process [START_REF] Hesse | Outside the Box: Will Information Technology Be a Viable Intervention to Improve the Quality of Cancer Care?[END_REF], lack of methods or algorithms to evaluate the quality of imparted information [START_REF] Marshall | Health Information: Does Quality Count For The Consumer? How Consumers Evaluate the Quality of Health Information Materials across a Variety of Media[END_REF], and insufficient level of confidentiality [START_REF] Agichtein | Finding high-quality content in social media[END_REF] are a number of material features of social media that contribute in the barriers constraints.

These technological features need to be coupled with some important social aspects of chronic care management to enact as barriers. Social features such as legal issues [START_REF] Thompson | Protected Health Information on Social Networking Sites: Ethical and Legal Considerations[END_REF], health literacy [START_REF] Chiarella | Using Web 2.0 to Create an Autism Resource[END_REF], and age [START_REF] Correa | Who interacts on the Web?: The intersection of Users' Personality and Social Media Use[END_REF] can influence users' perceptions about the capabilities of social media, and the ways they could assist or harm patients and carers during the management process.

The barriers constraint helps to explain the potential harm that the use of social media can cause of patients and carers. By examining this constraint(s) across diverse actors, it should be possible to identify features or functionalities of social media that are potentially insignificant or damaging to patients and carers and may adversely impact chronic care management. Also, it helps to understand the social concerns that the causes that improvises or diminishes the potential values of applications of social media in chronic care management.

It is noteworthy that these barriers and affordances are not permanent, but they are dynamic as the relations between the material agency of social media, and the social agency of the patients and carers can change [START_REF] Barad | Posthumanist Performativity: Toward an Understanding of How Matter Comes to Matter[END_REF]. In fact these affordances (constraints) that enact through such a relationship can also be a factor in changing the perceptions of users about the affordances of social media and therefore, the nature of users' perception about the affordances and constraints of social media can change over time. This change of perception, however, is yet influenced by users' new understandings of the material aspects of social media and how they can enact in a dynamic relationship with the social aspects chronic care management.

Conclusion

The question we aimed to answer in this study was: How can social media support communities of patients and carers that form around the complex process of chronic care management? Our investigation revealed that social media can play a supporting role in a number of ways including enabling patients and carers to build a sense of community, provide emotional support to each other, empower one another, and also assist each other to access, share, and search for the information they need. We also observed that social media did not always play a supporting role, and could create concerns around their potential harm to patients and carers. By focusing on its key findings of emotional support, empowerment, and barriers, this study also highlighted how these three aspects of social media use can influence the process of chronic care management. In explaining these key findings, we adopted an affordance perspective. This approach furnished us with a set of analytical concepts that put stress on inseparability of technological and social aspects of social media. The affordance perspective also allowed us to base our understandings on our participants' perceptions about the potentials of social media, emancipated us from framing and packaging their views within pre-defined concepts and constructs that attempt to establish superiority of either technology or social over the other. Our finding show that social media does not always play supporting roles to chronic care management but they may sometimes act as obstacles and barriers to the management process. These roles, however, are not permanent and fixed but can change as patients and carers learn more about themselves and the capabilities of social media. Our findings suggest that there is a dynamic relation between the contrary roles that social media can play in chronic care management and this is not only attributed to the functionalities of these technologies but to the attributes of patients and their states of health. This sociomaterial characteristic of social media can have implications for the design of these technologies as well as for their applications in healthcare communities.

By focusing on the role of social media in the context of chronic care management, we were able to observe how these technologies are bounded up with human activities in the ways that separating them is not possible. What we learnt from our findings (for example, how empowerment or barriers are perceived) is that the ways patients and carers use of social media can change their perceptions about their conditions, and also influence how they understand and approach the management process. In other words, social media is not seen just as technological artifacts, but as an aspect of the management process that constructs the every experiences of having chronic disease for patients and carers. At the same time, these experiences identify how social media can support or prevent the outcomes of the management process to be achieved.

We believe this study makes two major contributions. First, it expands our analysis and knowledge of the role of social media in supporting healthcare communities in ways that investigating either social media or healthcare communities alone does not. Second, this study provides insights into how social media can assists the future design of possible toolkits aim to help the patients and carers to build their own self-managed communities. For instance, our identification of certain barriers would imply that any self-managed community would have to be prepared to help and support patients to minimize the possible emotional discomforts or the social pressures that may occur by the use of social media. As another instance, considerations have taken into account by the community to make sure that patients felt comfortable with legal issues. We also argue that the findings of this study are transformable to communities within similar social context [START_REF] Lincoln | Naturalistic Inquiry[END_REF].

Communities are dynamic social entities. So, we believe the findings of this study can be used to conduct further research on how the use of social media can influence the dynamics and attributes of communities (e.g. resilience, sustainability, or adaptability), especially those that exist or form in complex and uncertain environments.

Fig. 1 .

 1 Fig. 1. Overview of the coding process

Fig. 2 .

 2 Fig. 2. An overview of the development of the Role of Social Media theme

Table 1 .

 1 An overview of the data collection and data sources

	Data source	Number of items/	Type of stories/participants	Stage
		participants
	Focus group	10 participants	10 arthritis patients	Exploration
	Arthritis forum	68 stories	31 patients, 25 carers, 9 nurses,
			2 physiotherapists, 1 rheumatologist
	Diabetics forum 64 stories Depression forum 29 stories Asthma forum 28 stories Breast cancer 34 stories forum	36 patients, 13 carers, 9 nurses, 1 GP, 4 social workers, 1 allied health 21 patients, 8 carers 21 patients, 5 carers, 2 nurses 23 patients, 5 family members, 4 nurses, 2 allied health	Conceptualisation
	Interviews	9 participants	5 practitioners, 2 patients, 2 carers	Theorising/
				corroboration

Table 2 .

 2 Examples of supporting evidence of the key findings

	Open code	Sample quote	Sub-category	Category
	Source of comfort It's been more of a source of comfort actually
		than a lot of the other resources which I found on
		the Internet


Stefan Stieglitz
email: stefan.stieglitz@uni-muenster.de

Deborah Bunker
email: deborah.bunker@sydney.edu.au

Milad Mirbabaie
email: milad.mirbabaie@uni-muenster.de

Christian Ehnis
email: christian.ehnis@sydney.edu.au

Communication Roles in Public Events -A Case Study on Twitter Communication

Keywords: Milad Mirbabaie, Christian Ehnis, social media analytics, Twitter, public events, emergency service agencies (ESA), social network analysis

à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Introduction

There is no doubt that social media has been adopted by many people in order to exchange information that is both timely and topical. The mass usage of social media is of course underpinned by the low transaction cost for the sharing of information (i.e. ubiquitous access, negligible monetary costs of devices and telecommunications, low time investment). The emerging and swift diffusion of mobile devices, such as smartphones, further lower these costs and lead to increasing rates of ad-hoc information being shared [START_REF] Stieglitz | Social Media Analytics: An Interdisciplinary Approach and Its Implications for Information Systems[END_REF]. As a result social media is having an increasing impact on communication during public or extreme events. Examples of such events could be public holiday celebrations, public disturbances and demonstrations, or large public crowd incidents such as the Boston Marathon bombings in 2013 [START_REF] Ehnis | The Impact of Disaster Typology on Social Media Use by Emergency Services Agencies: The Case of the Boston Marathon Bombing[END_REF]. Witnesses to a public event often share text based information or use their smart phones to share photos within seconds of an incident occurring. From our current understanding of social media use for personal communication we know that social media are not a one-directional information channel. Increasingly, social media communication has a material effect on unfolding events, and for better or worse this has an impact on the management of, and response to an event. In this sense, social media increasingly becomes an additional source of information that must exist beside traditional "command and control" systems.

It is now becoming critical to understand underlying principles and knowledge about social media communications and how these impact and affect the participation in and management of public events. Until now, there has been very little research conducted to better understand the role of event participants when they communicate via social media i.e. it is unclear if social media communications by individual event participants have differing levels of influence or impact on other individual event participants. To this end, our study analyses the "1st of May" public event (German Labour Day 2014) Twitter data to identify participants and the roles that they played in the event via social media. We decided to analyse this public event, because it has characteristic of an extreme event, but is predictable in its unfolding through experience from previous years. The paper proceeds as follows: Section 2 outlines related work in the field. Section 3 describes the 1st of May case; Section 4 explains our research design; we then present our analysis in section 5 and our findings in Section 6. The paper ends in Section 7 with conclusions and an outlook for further work in the area.

Using Social Media to Communicate During Extreme Events

We are observing an emerging trend for individuals and groups to use social media to communicate during extreme events and crises [START_REF] Stieglitz | Analysis of Sentiments in Corporate Twitter Communication -A Case Study on an Issue of Toyota[END_REF]. Social networking platforms (Facebook and Twitter), mapping (Ushahidi and Google) and wiki and mash-up technologies; have enabled one-to-one, one-to-many and many-to-many communications frequently resulting in collaborations. For example we have seen the adoption and use of these platforms and technologies by NGOs, for eco-collaboration activities [START_REF] Aoun | From Cloud to Green: E-Collaboration for Environmental Conservation[END_REF]. These collaboration technologies were used in a structurally dynamic manner depending on the NGO national context (Thai, Lebanese and Australian). We have also witnessed individuals and groups using social media platforms during the civil uprising of the "Arab Spring" i.e., Tunisia 2010/11 and Egypt 2011 [START_REF] Bunker | Serendipity in Disaster and Complex Scenarios[END_REF] and the current uprising in the Ukraine and Crimea 2014. As a result, traditional centralized "command and control" systems, used by government agencies during events, crises and disasters, must now deal with, make sense of and utilize the proliferation of information generated by organizations, groups and individuals on open and freely available communication and collaboration platforms. Indeed, in order to ensure successful event, crisis and disaster management outcomes, it is imperative that non-agency organizations, groups and individuals constantly provide accurate and reliable information to government agencies, and receive accurate and reliable information from these agencies in return [START_REF]Sydney Alliance: Half a Million Sydneysiders to Create Change and Opportunity and Improve the City[END_REF]. For example, during the 2011 Queensland Floods [START_REF] Ehnis | Social Media in Disaster Response: Queensland Police Service -Public Engagement During the 2011 Floods[END_REF], there were reports of the difficulties of government agencies in communicating with and engaging local communities to firstly obtain and then incorporate local knowledge on floods, into emergency agency decisions. This may have contributed to higher than necessary the loss of life and property for some communities [START_REF] Campbell | Local Knowledge Needed in Grantham[END_REF].

The case of the formation and role of the Student Volunteer Army (SVA) during the Christchurch Earthquakes (2010/2011), is one of many cases that motivate us to examine how to best encourage effective communications between government agencies, organizations, communities, groups and individuals during an extreme event [START_REF] Bunker | Crisis Management and Social Media: Assuring Effective Information Governance for Long Term Social Sustainability[END_REF]. In the case of the SVA we see the development of situational awareness, utilization of resources and optimization of crisis management outcomes through the inter-play of communications via social media platforms and the subsequent input of the resulting information input into proprietary (and closed) government systems. The SVA was formed by the use of social media in the wake of the Christchurch earthquakes (September 2010 to June 2011). Bunker et al. [START_REF] Bunker | Crisis Management and Social Media: Assuring Effective Information Governance for Long Term Social Sustainability[END_REF] studied and analysed the first few weeks of Facebook and Twitter activity by the SVA after the February 2011 Christchurch Earthquake (the major disaster event in the earthquake series throughout 2010/2011). This analysis highlighted the power of harnessing community ethos, goodwill, motivation and momentum through open communications via social media, as the prime focus of interactions between the SVA and disaster management agencies.

A recent European example of the complex impact of social media on participant communications are the London riots of August 2011, which saw four days of the worst violence and destruction in the UK's recent history [START_REF]The Guardian: Reading the Riots: Investigating England's Summer of Disorder[END_REF]. These riots have been seen as a response to the perceived neglect of public needs by a government implementing severe austerity measures [START_REF] Payne | London Riots: Incidents and Suspects Mapped in the UK[END_REF] and were triggered by the shooting of Mark Duggan by the London Metropolitan Police. In the course of these riots, social media were used both by rioters to purposefully organise unrest and looting by UK citizens, and by law-abiding individuals to purposefully share advice about the safety of local areas, organising the post-riot clean-up, and to support local businesses whose shops had been looted or torched. The UK government admitted that it was unable to effectively monitor social media services, and briefly considered shutting down access to Facebook and Twitter [START_REF] Payne | London Riots: Incidents and Suspects Mapped in the UK[END_REF][START_REF] Halliday | Facebook and Twitter to Oppose Calls for Social Media Blocks during Riots[END_REF].

Data analysis from all of these case examples clearly highlight that during public events, effective communications via social media platforms must be:  Accurate, reliable, timely and two-way (between agencies, organizations, groups and individuals);  Influential and capable of harnessing positive thoughts and ideas (business and community ethos and goodwill as well as individual motivation); and  Purposeful and intentional (for well-organized activity). This of course helps us to understand the characteristics of effective "messages" and communications propagated through the use of social media platforms during extreme events. We know very little, however, about the characteristics of, or roles played by event participants when they communicate through the use social media platforms.

Barley [START_REF] Barley | The Alignment of Technology and Structure through Roles and Networks[END_REF] discusses a role-based approach to the impact of technology on work tasks which is grounded in Nadel's [START_REF] Nadel | Bürger feiern, Gewerkschafter mahnen, Demonstranten stören die NPD[END_REF] work into relational and non-relational roles. He argues that roles:  Are grounded in daily-life interactions;  Are intimately bound to social relationships;  Are partially defined by task performance (but subsumed an individual's skills);  Allow an analysis of not only technological material implications but also how technological constraints are transformed into social processes; and  Offer a set of inter-related concepts to help define links between adjacent levels of analysis [13, p. 68].

A role focussed approach to the analysis of social media use for public events, would allow researchers to focus on how event participants use such technological platforms to interact and communicate; carry out social relationships (and social processes); and perform various tasks against the background of specific events.

Relational roles (as defined by Nadel) must have a "specific other" e.g. a son must have a mother, while a non-relational role exhibits behaviours that are indicative of that role e.g. a professional class such as an accountant, lawyer etc. Barley concludes, however, that all roles are "bundles of non-relational and relational elements [13, p. 68] so it is difficult to arbitrarily separate the two.

In the case of a public event, we would assume that various participants would have roles to play, some of which would be relatively predetermined and well defined i.e. government agencies, and some of which would have emergent characteristics i.e. selforganising community groups, social activists etc.

Barley highlights that researchers studying the impact of technology on role-based (organisational) structures must focus on 3 elements which directly impact roles: 1) how technologies influence tasks, skills, and other non-relational aspects of roles; 2) how these changes influence the relationships between roles; 3) how properties of the social network determine role relations and the structure's (network) configuration. These 3 elements, he argues "either sustain or modify" structures such as networks as they are the "blueprints for ongoing action" [13, p. 70].

So what role does the "messenger" play in these communications? In order to address this shortcoming in our knowledge, our study has looked at participant roles and the use of social media during the "1 st of May" Labour Day public event in Germany.

Case Study

The 1st of May is a public holiday in Germany celebrated as Labour Day. Traditionally there are Labour Day rallies and marches in many German cities. Most of the rallies and marches are peaceful events, however, historically several radical groups become violent in some of these marches. The city districts of Berlin and Hamburg specifically have a history of marches that have turned into violent riots. Because of this history the local police forces in these two cities are always supported by federal and other state police forces to contain any potential violence.

In contrast to previous years, besides a few local incidents, the 1 st of May 2014 Labour Day marches were generally peaceful events [15]. In the evening a march in Hamburg turned violent and was ended by the police [START_REF] Morgenpost | Polizei setzt Wasserwerfer gegen Demonstranten ein[END_REF]. In Berlin the two biggest 1 st May related events were a march with about 19,000 participants and the festival "myFest" with about 40,000 participants. The police in Berlin were pleased with the peaceful atmosphere of both events [START_REF] Hasselmann | Polizei "zufrieden und glücklich" nach Großeinsatz[END_REF].

Research Design

In order to understand the different participant roles in the '1 st of May' event and their use of social media to communicate, collaborate and organize, we use an exploratory research approach for data collection and analysis. We firstly accessed Twitter, a widely-used and popular micro-blogging platform according to the "total number of active registered Twitter users" [START_REF]Statisticbrain: Twitter statistics[END_REF], to collect the data for our dataset. We did this by utilizing a self-developed software tool, which collects data through the Twitter Search API by using specified keywords in order to find relevant tweets (on the 1 st of May topic). Data tracking started on the 28th of April 2014 and ended on the 5 th of May 2014. This timeframe ensured that the most important content regarding the 1 st of May topic was collected over a time period leading up to and after the event. All keywords were tracked and merged into a single dataset for further analysis. As the selection of keywords directly influences the data that are collected we ensured that our keywords were carefully selected to effectively target the relevant data for the event. For example it is very important not to choose keywords that have different meanings in different contexts. Furthermore, the Tweets (in this case) were required to be directly linked to the event to avoid including any unrelated data. For this study we selected 6 keywords: 3 of these describe the event itself; and 3 described locations that were related to the event. Our keywords are presented in Table 1. Our data set included a total number of 13,413 Tweets generated by 7,734 accounts (participant nodes). After collecting the data, we prepared them in Excel in order to investigate the influence of certain participants in the event and the role they played i.e. ESA, organization, community group, individual etc. related to communication via social media.

Analysis

We conducted a social network analysis (SNA) to get an overview of the data and to detect the most important participant nodes in the network by role. To visualize the network, we used Gephi, a tool that is available as open source software for graph visualization. The participant nodes of the network reflect the primary sources of tweets and the edges of these nodes were defined as re-tweets.

The following Figure 1 represents the SNA, which illustrates the participant nodes and the edges as the re-tweets. One of the "Individual" accounts for example has retweeted most (indicated by the size of the bubble), but was re-tweeted from small number of participant nodes (indicated by the gray gradation). Another example would be the account "Emergency services agency" (here the Police of Berlin) that represents a node, which has been re-tweeted very frequently by other accounts and which retweeted other postings very rarely. In order to obtain a clearer overview of the data we then ran an algorithm (ForceAtlas 2) in Gephi and used the participant node tweet in-and out-degree functionality. The in-degree implies the degree of how much a participant node has been re-tweeted, whereas the out-degree describes the degree of how much a participant node has retweeted. In our network analysis we defined the node in-degree in the colour grey (the bubbles and arrows) with the size of the bubbles signifying the node out-degree. Table 2 illustrates our analysis of the dataset as it relates to key Twitter accounts (participant nodes). Based on our analysis we have highlighted the following influential network participants based on the number of re-tweets (Table 3). The account was twittered second most by a single person who also retweeted "PolizeiBerlin_E" 9 times There was participation of a grocery store node that can be categorised as a commercial organisation There was a single tweet in the dataset, with a high re-tweet rate "Für alle, die am #1Mai eine Überdosis Pfeffer erwartet, wir haben auch Salz!" (English: For those who will have an overdose of pepper at the '1 st Mai', we also have salt!)

The grocery store used the attention of the crowd in order to make some advertising There was a participation of a real estate company node which represents a political group They are highly motivated to stop rising rents in Hamburg, Germany "Welcome center im karoviertel eröffnet! Hamburgs größte Hausbesetzung! #1Mai #1maihh" (English: "Welcome center opened in Karoviertel! Hamburg's largest house squatting!)

The account tries to get some attention of the people, during the '1 st

Discussion

Our findings reveal interesting communication behaviour and emerging participant roles during the 1st of May event. The results of the SNA, the statistical analysis and further analysis of the primary participant roles indicate that ESA (in our study PolizeiBerlin_E) are central to the event and are frequently re-tweeted on Twitter. The Berlin Police while generating the 4th largest number of tweets (Table 2) actually generated the 2nd largest number of re-tweets (Table 3).

The Berlin Police have a non-relational role to play in the 1 st of May event exhibiting behaviour that is typical of Police communications with the wider community. This is manifested in the topics and content of Police tweets. The characteristics of the Police tweets in this dataset (table 2) can be classified into following types: The Police communications behaviour in turn influenced the relationship between various participant roles in the Twitter network as both the SNA and the statistical analysis indicate a "Megaphone Effect" of Police communications i.e. twittering a few tweets which are then re-tweeted by many participant nodes very often.

Another important finding shows the relationship of the top 5 participant roles and the number of their tweets (Table 2). This list is dominated by media (news), but none of the media participants have a significant effect on the 1st of May topic as highlighted by their low tweet in-degree. Only the left-oriented media roles, have a highly significant effect on the tweets and thus on the participants who re-tweet their tweets.

We also identified some individual participants and small groups who were very active according to the number of their tweets but which were not re-tweeted at all. An interpretation of this finding might be that, they were not noticed by other participants in the event because their role (and communications) in the event had no meaning to other participants. There was also a very low participation rate in the event (at least via Twitter) of extreme right-wing participants. Most of the active participants in our dataset seemed to be strongly left-wing oriented. This may be accounted for by the role of mainstream political organisations and the willingness (or otherwise) of non-mainstream participants to public commitment to beliefs.

Finally, we found that a European supermarket used the event and participation in it via Twitter, to advertise for their brand. With a single tweet, which was re-tweeted 137 times, they were able to attract highly effective attention to their products without incurring the usual advertising costs. Their role as a commercial business was effective in using the network to propagate marketing information.

As we can see by this analysis, the properties of the Twitter social network (the notion of tweeting and being retweeted) have an effect on the role relations and the network configuration.

Conclusion

Our analysis gives an initial overview of how participants in the 1st May 2014 event in Germany used social media (Twitter) to communicate. We have also been able to highlight 1) how Twitter influenced the behaviour of the non-relational Police role; 2) how this non-relational role (in the network) influenced the relationships between participant roles; and 3) how properties of this Twitter network (the notion of tweets and retweets) have determined role relations and network configuration.

We are currently performing a more detailed analysis of the communication practices of participants in this event as well as their role characteristics (emergency services agencies, media organisations, political groups and unions, individuals and commercial organization). We are specifically analysing what kind of messages are most often generated and shared and what kind of messages are ignored (and by whom).

So what of the 'messenger'? From our initial analysis we can now better understand that roles, their relationships and the social network structure in the use of social media platforms (in this case Twitter) during an event such as the 1st of May. We also understand that the volume of tweets by an event participant does not necessarily translate into attention or influence as defined by re-tweeting (and in-and out-degrees). Obviously there is some interplay between the role played by the event participant and the characteristics of effective social media communications. Our further research and analysis will focus our investigations on this interplay.

As with every study there are limitations. The event we have chosen to analyse is a public event which is relatively planned and well-controlled. It has given us an opportunity to evaluate roles through the use of social media with a smaller scale dataset, which may not be able to be effectively scaled up to a less controlled and more chaotic event (such as a riot or crisis event). Our initial analysis has also been based on the identification of tweets and re-tweets by keyword. Whilst this can be helpful to gain an initial understanding of event participants and their roles and influence via Twitter, it gives us none of the subtle understanding or context behind the contents of each tweet. The next stage in our analysis will seek to address this limitation. We must also understand the roles of event participants who did not seek to communicate via Twitter (for example right-wing political groups) and why this was the case, so as to better understand the reasons for, and motivations behind event participant selection and use of social media such as Twitter

Fig. 1 .

 1 Fig. 1. Social network analysis -1 st of May (Labour Day)

1 .

 1 Event Information:  Start and end of a demonstration: "Der 18 Uhr-Aufzug hat soeben mit einer Kundgebung am Lausitzer Platz begonnen."  Number of active police officers: "...6.400 Polizistinnen und Polizisten sind heute rund um den #1Mai im Einsatz."  Number of participants: "Die "Revolutionäre #1Mai Demo"befindet sich aktuell mit ca. 19.000 Personen..."  Location: "...auf der Zossener Str. in Richtung Hallesches Ufer." (English: address-names) 2. Traffic Information "Der Görlitzer Bahnhof ist momentan noch gesperrt. #1Mai #MyFest #BVG" (English translation: Goerlitz central station is closed at the moment…) 3. Warning "Aus der "Revolutionären #1Mai Demo heraus werden vereinzelt Pyros gezündet, Flaschen und Steine auf Polizist*innen geworfen." (English translation: Pyrotechnics are used in the 1May demonstration…) 4. Behaviour influencing "Bitte meiden Sie den #Hermannplatz ab 18:30 Uhr weiträumig, da er für eine Demo komplett gesperrt wird. #Neukölln #Verkehr #1Mai" (English translation: Please avoid the #Hermannplatz (location) from 6:30 pm widely, since it is completely blocked for a demo…")

Table 1 .

 1 Keywords for Twitter data collection (by category)

	Category	Keyword	Reason / Meaning
	Event	1Mai	Main topic/date
	Event	1Mai_nazifrei	National socialists use this day in order to demon-
			strate. This keyword is used by individuals who to op-
			pose the Nazi movement
	Event	Tag_der_Arbeit	Labour movement
	Location	Feuerwehrbrunnen	Hot spot for demonstration in Berlin, Germany
	Location	Mariannenplatz	Hot spot for demonstration in Berlin, Germany
	Location	Rote Flora	Hot spot for demonstration in Hamburg, Germany

Table 2 .

 2 Data analysis

	TwitterAccount	Number of	In-degree	Out-degree
	(participant node)	tweets	(was retweeted)	(has retweeted)
	Sorted by in-degree
	Media organisation	42	266	1
	Emergency services agency	31	238	0
	Commercial organisations	1	137	0
	Political group	25	105	1
	United service union	28	102	18
	Media organisation	7	80	1
	Media organisation	12	77	1
	Individual (politically engaged)	47	76	3
	Media organisation	7	70	0
	Individual (politically engaged)	37	69	15
	Sorted by out-degree
	Individual (politically engaged)	52	0	52
	Individual (politically engaged)	67	0	45
	Individual (politically engaged)	64	2	39
	Political group	36	0	35
	Individual (politically engaged)	38	1	31
	Individual (politically engaged)	29	0	29
	Political group	57	19	27
	Media organisation	22	0	22
	Individual (politically engaged)	23	0	21
	Political group	34	8	21

Table 3 .

 3 Key findings

	Influential	Description	Example Tweets	Further
	Network			Information
	Participants
	The account of a	The node	".@GregorGysi: Botschaft	It was twittered most by
	Media	represents a left-	des #1Mai lautet, "dass man	a politically engaged
	organisation was	oriented	sich nicht länger alles bieten	individual, which is also
	re-tweeted most	newspaper named	lassen darf""	the account that re-
		"neues	(English: The message of the	tweeted most in our
		deutschland"	'1st May' is that you do not	dataset. It is not clear, if
		(English: "The	have to put up with	this node is a single
		New Germany")	everything)	person or a media outlet,
			"#1Mai: Polizei kesselt in Plauen Gegner der Nazidemo	but it was very active regarding political topics
			ein #pl1mai"
			(English: Police encircled in
			Plauen opponents of the Nazi
			demonstration)
	The account	This account	"Ca. 10.000 Teilnehmer/in-	The account was
	'PolizeiBerlin_E'	represents the	nen der "Revolutionären	twittered most by a
	(a emergency	official account of	#1Mai Demo" erreichen	media organisation (18
	services agency)	the police of	gleich den Hermannplatz."	retweets of
	was re-tweeted	Berlin	(English: Around 10,000	"PolizeiBerlin_E"), a
	second most, but		participants of the"	boulevard newsmedia
	twittered only 31		revolutionary '1st Mai'	outlet which is a 100%
	times		Demonstration are going to	subsidiary of the Axel-
			reach the Hermann Square)	Springer AG (B.Z.
				Ullstein GmbH 2014)