Bert P Groot

Robin Effing

] Mettina

J A Veenstra

Urban Media Trends for Enabling Citizen Participation in Urban Planning: Old Wine in New Barrels?

Keywords: Smart city, Urban Media, Citizen Participation, Area Development

In recent years, a plethora of new possibilities for interactive urban planning emerged, fuelled by the rise of smart cities. This paper studies the potential of urban media for reshaping the role of citizens in urban planning. Both the historical role that citizens have played in the development of neighbourhoods and the process of urban planning are presented from a literature review. Furthermore, present visions on urban planning and citizen participation in smart cities are reviewed. Lessons learned from this literature study, are confronted with six main trends in urban media from expert interviews. As a result, we deliver an overview that helps urban planners in neighbourhoods in order to profit from advantages of urban media while avoiding their risks. We found that the development of urban media could have both positive and negative effects with regard to citizen participation in urban planning in neighbourhoods.

Introduction

Citizens have become smarter due to their access to the internet, social media and other digital media, in particular in cities. Both the rise of the smartphone and mobile internet access have reshaped city life. Ever more cities develop specific strategies for bearing the fruit of smart and digital consumer technologies in a wide variety of policy fields and in spatial development [START_REF] Cardullo | Being a "citizen" in the smart city: Up and down the scaffold of smart citizen participation[END_REF]. Well known cities, often mentioned in literature as smart cities, are cities such as Barcelona, Amsterdam, Songdo, London and Masdar [START_REF] Lange | Owning the city: New media and citizen engagement in urban design[END_REF][START_REF] Angelidou | The Role of Smart City Characteristics in the Plans of Fifteen Cities[END_REF]. Parallel with the increase of the possibilities for cities and local governments to become smart cities the possibilities for its inhabitants to become a smart citizen keep increasing as well [START_REF] Effing | Social smart city: Introducing digital and social strategies for participatory governance in smart cities[END_REF][START_REF] Foth | Citizens breaking out of filter bubbles[END_REF][START_REF] Foth | From Users to Citizens[END_REF][START_REF] Ahlers | Understanding Smart Cities As Social Machines[END_REF]. The online toolkit available to smart citizens, can radically reshape the way they engage in the development of their own living environments. Urban media interactions are a key part of such an online toolkit. Urban media is a term that describes a wide variety of 'new' media that influence the use of public space. Examples of such media are mobile smartphone apps, social media, virtual reality and augmented reality [START_REF] Lange | Owning the city: New media and citizen engagement in urban design[END_REF][START_REF] Waal | De Stad als Interface Digitale Media en Stedelijke Openbaarheid[END_REF].

In today's networked society, as introduced by Castells [START_REF] Castells | The Rise of the Network Society[END_REF], citizens tend to gain a more central role in urban planning [START_REF] Waal | De Stad als Interface Digitale Media en Stedelijke Openbaarheid[END_REF]. The combination of these developments raise the question what the impact of urban media is on urban planning practices. Therefore, the main question of this article is; What is the added value of urban media trends for citizen participation with regard to area development within existing neighbourhoods? The main aim of this research is to gain insight in the opportunities and risks of the use of urban media, within the process of area development in neighbourhoods. More specifically, on the role of citizen participation. The research method consists of both literature review and qualitative research with experts. First, in the beginning of 2017, we performed a literature review concerning the involvement of citizen in area development. Insights in area development in neighbourhoods were derived from experts in policy making and area development. Since Hajer warned that "the smart city discourse is notoriously weak on historical awareness" [START_REF] Hajer | Smart About Cities. Visualising the Challenge for 21st century urbanism[END_REF], we have chosen to start the literature research with insights gained in early twentieth century. Also, contemporary literature was included with topics such as smart cities and area development. The second part of the study was based on qualitative expert interviews. Eight experts were interviewed regarding trends and developments with respect to urban media. These interviews were conducted in a face-to-face setting and used a semi-structured list of questions. Experts were selected from fields of expertise including area development in smart cities, participatory smart city developments and ICT. Expert interviews led to the definition of six relevant trends in urban media. Those trends were then confronted with the characteristics of area development.

The remainder of this article is structured as follows. In section 2 we introduce a theoretical background. In section 3 we will introduce the trends in urban media. In section 4 we show an analysis of the findings. The final section is discussion.

Theoretical background

The key concepts of this research are urban media, citizen participation and area development. We are aware of the vast amount of literature that covers the opportunities and pitfalls of e-participation and smart cities. We did not strive to provide a comprehensive overview of that body of literature. We focus completely on the new opportunities of Urban Media for area development in neighbourhoods. The term urban media is relatively new and has a relatively small base in literature. In 2018, only 81 peer-reviewed articles can be retrieved from Scopus mentioning this term in the abstract, keywords or title.

Participation in area development

Throughout the history of mankind, the quality of life in cities has been a matter of concern for city planners. Also, citizens influenced their own living areas. In early models, city planning was a heavily rationalized process, developed in a top-down manner. Urban designers presented blueprints of housing areas that needed to create a living area for the rapidly growing cities. The role of citizens in the development of these plans was marginalized [START_REF] Alexander | After rationality[END_REF]. Models that had quality of life and diversity for inhabitants in mind started in late 19th century when industrialization created very bad living circumstances in rapidly growing cities. Ebenezer Howard proposed his famous model of Garden Cities in 1898. A model that he created as a reaction on the poor living conditions in English cities, such as London. His solution was to create a network of satellite cities with a maximum of 32000 inhabitants, surrounded by large green areas [START_REF] Waal | De Stad als Interface Digitale Media en Stedelijke Openbaarheid[END_REF].

One could say that he would almost abolish cities, in favor of good living conditions for inhabitants. Not much later Le Corbusier proposed an opposite approach to the problem of dense and polluted cities of that time. His plans for 'La ville radieuse' and 'La ville contemporaire' proposed the development of megacities with millions living in it but build up as large buildings surrounded by massive green areas, thereby creating a livable space for inhabitants. The problem both plans tried to solve was the same: to create better living conditions for the people in the cities [START_REF] Cammen | Ruimtelijke ordening van grachtengordel tot Vinex-wijk[END_REF]. The CIAM-congresses in Europe or the mass development of New York under supervision of city planner Robert Moses, generated urban development plans regarding livable neighbourhoods for citizens. All of them doing so without actual participation of citizens. Much of the large-scale expansions of cities, pre and post-world war two, where developed in that way [START_REF] Brooks | Planning Theory for Practitioners[END_REF].

In the second half of the twentieth century a shift took place in the views on area development. Most prominent under the influence of Jane Jacobs, after she wrote her famous book "The Life and Death of Great American Cities" in 1961. [START_REF] Jacobs | The Death and Life of Great American Cities[END_REF]. This created a more central role for citizens in the process of city planning. Her plea for more actual involvement of citizens within the process of city making gained much acclaim and follow up. In 1965, Davidoff presented his influencing model of Advocacy planning [START_REF] Davidoff | Advocacy and Pluralism in Planning[END_REF]. A planning model that plead for more equality in urban planning. The model emphasizes the importance including the interests of several target groups living in urban areas [START_REF] Davidoff | Advocacy and Pluralism in Planning[END_REF]. Jacobs and Davidoff stressed that a broad representation of the public and participating in creating livable living conditions are crucial factors.

Already in 1969, Sherry Arnstein was the first to introduce a participation ladder theory to describe various levels of influence citizen can have in a policy making process [START_REF] Arnstein | A Ladder Of Citizen Participation[END_REF]. Her model was widely accepted and evolved into several adaptations of the model including e-participation ladders. However, there is not much consensus within those different ladders [START_REF] Grönlund | ICT Is Not Participation Is Not Democracy -eParticipation Development Models Revisited[END_REF]. An important lesson was that citizens could take different roles in the participation process [START_REF] Pröpper | De aanpak van interactief beleid: elke situatie is anders[END_REF].

New relations between citizen and government

In the last decade, another shift in the planning discourse can be acknowledged towards citizen leadership in urban development, particularly in neighbourhoods. Terms such as co-creation or grassroots initiatives describe this process [START_REF] Lodigiani | E-Planning: The Digital Toolbox in Participatory Urban Planning[END_REF]. In a new planning philosophy called radical incrementalism, a shift takes place in de the roles of government and civil society [START_REF] Hajer | Planbureau voor de Leefomgeving[END_REF]. Unlike models of the past, governments do not propose blueprints of policy, but set wider, larger scale goals. Every project, initiative or experiment that seems beneficial for achieving these goals, is approached in a cooperative manner. Experiments that succeed, could be learned from and if scalable, implemented on a larger scale. The dynamics of contemporary society functions as a catalyst for new ideas, projects and initiatives. Through process of trial and error, society learns what could be implemented successfully and what not. The model is based in the principles of incremental planning [START_REF] Lindblom | The Science of Muddling Through[END_REF]. The model of radical incrementalism teaches us that a shift in ownership for policymaking and area development is necessary. Therefore, three principles regarding new relations between government and civil society are [START_REF] Hajer | Planbureau voor de Leefomgeving[END_REF]:

1. Acknowledge the paradigm of the energetic society, for both finding solutions as in approach to policy challenges; 2. Attach to the experiences of the citizen; 3. Consider the societal dynamics as a catalyst for solutions, not for problems.

In this new relations and field of influence it is important for local governments to be clear in the role they take in different projects with regard to area development.

The smart citizen

With the rise of smart cities and its possibilities, the position of citizens change [START_REF] Cardullo | Being a "citizen" in the smart city: Up and down the scaffold of smart citizen participation[END_REF]. Together with the previously described changing discourse in urban planning and area development, the role citizens can play in the development of their own neighbourhoods can be redefined. As Castells described, internet and connectivity transformed our society into a network society [START_REF] Castells | The Rise of the Network Society[END_REF]. The network society gives increasing opportunities and freedom of choice in groups to which we can bind ourselves and to which we feel connected. A process described by Wellman as networked individualism [START_REF] Wellman | The Social Affordances of the Internet for Networked Individualism[END_REF]. The individual citizen functions as a switchboard between the different networks. This creates a very strong, horizontally oriented organizational structure that could be used for citizen to organize themselves, improve experiments, exchange ideas and learn [START_REF] Brafman | The Starfish and the Spider: The Unstoppable Power of Leaderless Organizations[END_REF]. This provides the citizen with instruments creating possibilities that makes bottomup area development possible. A process Townsend describes as a do-it-yourself-city [START_REF] Townsend | Smart cities. Big data, civic hackers, and the quest for a new Utopia[END_REF]. The do-it-yourself-city is strengthened by the strong organizational structure of networked individualism. Townsend defines the do-it-yourself-city as 'a city that is not centrally operated, but a city that is created, operated and improved upon by all'. This shows that the impact of networked individualism, also affects the role citizens play in area development in their own neighbourhoods.

In the Datapolis [START_REF] Meijer | Bestuur in de datapolis: Slimme stad, blije burger? Boombestuurskunde[END_REF] approach, city's government is seen as a central body, that makes decisions based on the gathering of urban data. The Centro de Operacoes Rio in Rio de Janeiro is a remarkable example of this type of governing. The role of citizen is marginalized. The opposite of this approach is a city that is not controlled from the cockpit, but commences out of a whole of uncoordinated activities, like a swarm [START_REF] Meijer | Bestuur in de datapolis: Slimme stad, blije burger? Boombestuurskunde[END_REF]. This way of governing fits perfectly in the described shift in roles for citizen participation, and the shift towards networked individualism. Many authors now take an integrated perspective on smart cities instead of merely pushing technology. Caragliu, Del Bo and Nijkamp [START_REF] Caragliu | Smart Cities in Europe[END_REF] state that a city is smart when: "investments in human and social capital and traditional (transport) and modern (ICT) communication infrastructure fuel sustainable economic growth and a high quality of life, with a wise management of natural resources, through participatory governance." As Neirotti et al. made clear, a smart city can only be really smart when the city is capable of addressing real-life challenges and when it is able to bear the fruit of the social capital of the people involved in that city [START_REF] Neirotti | Current trends in Smart City initiatives: Some stylised facts[END_REF]. The involvement of smart citizens is essential. Smart citizens play a crucial role in smart cities by their participation in smart governance of local areas where they live or work [START_REF] Granier | How are citizens involved in smart cities? Analysing citizen participation in Japanese "Smart Communities[END_REF].

Smart citizen participation in neighbourhood area development

After the review of literature regarding the role of citizens in urban development in neighbourhoods, and analyzing the outcomes, we defined seven crucial aspects regarding the role of citizens in area development. These are:

1. Sufficient possibilities for citizens to participate [START_REF] Jacobs | The Death and Life of Great American Cities[END_REF][START_REF] Hajer | Planbureau voor de Leefomgeving[END_REF] 2. Clear definition of the level of participation [START_REF] Effing | Social smart city: Introducing digital and social strategies for participatory governance in smart cities[END_REF][START_REF] Arnstein | A Ladder Of Citizen Participation[END_REF][START_REF] Pröpper | De aanpak van interactief beleid: elke situatie is anders[END_REF][START_REF] Denters | Burgers maken hun buurt[END_REF] 3. Enough diversity in the group of participants [START_REF] Jacobs | The Death and Life of Great American Cities[END_REF][START_REF] Davidoff | Advocacy and Pluralism in Planning[END_REF] 4. Enough influence from minorities in a neighbourhood [START_REF] Jacobs | The Death and Life of Great American Cities[END_REF][START_REF] Davidoff | Advocacy and Pluralism in Planning[END_REF] 5. A broader government goal as a compass for area development [START_REF] Hajer | Planbureau voor de Leefomgeving[END_REF] 6. Enough institutional freedom to experiment [START_REF] Hajer | Planbureau voor de Leefomgeving[END_REF][START_REF] Lindblom | The Science of Muddling Through[END_REF] 7. Using the dynamics in society as a catalyst for participation [START_REF] Hajer | Planbureau voor de Leefomgeving[END_REF] 3 Results

Urban media can influence the experience, use and value of physical places in a city [START_REF] Waal | De Stad als Interface Digitale Media en Stedelijke Openbaarheid[END_REF]. Smartphones enable us to bridge both time and place. Apps are contributing to new forms of experience within neighbourhoods and could contribute to social cohesion (e.g. bridging and bonding social capital [START_REF] Ellison | The Benefits of Facebook "Friends:" Social Capital and College Students' Use of Online Social Network Sites[END_REF]). In today's society, the poster on a façade is replaced by the interface of a smartphone [START_REF] Dijck | De platformsamenleving[END_REF]. Urban media are developed into more personal, time and place independent, and more responsive forms of media. We conducted semi-structured interviews with eight experts for identifying trends in urban media. We aimed to explore the influence of urban media trends on area development.

Since the experts were regarded as authorities within the field of urban development or urban media, we decided to list all key trends in Table 1.

Table 1. Trends in Urban Media as indicated by field experts

Interviewee # Platform society

User generated content

Use of image and video

Trend 1. Networked individuals in a platform society

According to many of our interviewees, the networked society is shifting towards a platform society [START_REF] Dijck | De platformsamenleving[END_REF][START_REF] Dijck | The Culture of Connectivity: A Critical History of Social Media[END_REF][START_REF] Helmond | The Platformization of the Web: Making Web Data Platform Ready[END_REF]. The process of networked individualism makes citizen more and more footloose. A citizen does not necessarily bind himself to his neighbourhood. The perception of a place can commence even if one doesn't actually know a place, or even has been to a place. Through the omnipresence of media, a form of hybrid space is developed. The use of a smartphone as a territory device magnifies this effect. This even makes the definition of new groups of people possible [START_REF] Waal | De Stad als Interface Digitale Media en Stedelijke Openbaarheid[END_REF]. Most of the urban media on smartphones operate on a (online) platform. Van Dijck et al. [START_REF] Dijck | De platformsamenleving[END_REF] described this process as a shift towards a platform society. Helmond [START_REF] Helmond | The Platformization of the Web: Making Web Data Platform Ready[END_REF] speaks of 'platformification', in which societal, social, and economic life for major parts runs through platforms. Four main companies (Google, Amazon, Facebook and Apple) dominate the platform landscape. A downside of such platforms is the risk of creating so called filter bubbles [START_REF] Foth | Citizens breaking out of filter bubbles[END_REF], caused by recommender algorithms.

Trend 2. User generated content

Users generate all kinds of posts, textual or audio-visual, and share them via platforms such as YouTube and Instagram [START_REF] Kaplan | Users of the world, unite! The challenges and opportunities of Social Media[END_REF][START_REF] Wei | Knowledge Production and Political Participation: Reconsidering the Knowledge Gap Theory in the Web 2.0 Environment[END_REF]. User generated content is the fuel for smart cities. According to Kaplan and Haenlein [START_REF] Kaplan | Users of the world, unite! The challenges and opportunities of Social Media[END_REF], user generated content needs to fulfil three basic requirements in order to be considered as such:

1. It needs to be published either on a publicly accessible website or on a social networking site accessible to a selected group of people; 2. It needs to show a certain amount of creative effort; 3. It needs to have been created outside of professional routines and practices. This enables the growth of urban media, the mining of citizen generated data, partly as a result of urban media use, is growing. User-generated content can be used as possibilities for citizens to influence their own living areas. It can also be used for knowledge production in political participation [START_REF] Wei | Knowledge Production and Political Participation: Reconsidering the Knowledge Gap Theory in the Web 2.0 Environment[END_REF]. Furthermore, extensive analysis of user generated content, as described in the cockpit metaphor, makes policy-making possible whilst taking the ideas and interests of a large and diverse population into account that lives in a neighbourhood. When data is collected on a variety of topics and among a relevant group of people, a form of indirect citizen participation could be achieved.

Trend 3. The growing importance of image and video

Visual social media channels such as YouTube, Instagram and Snapchat are getting more popular [START_REF]Comscore: Global Digital Future in Focus[END_REF]. What those channels have in common is their emphasis on pictures and video as their most important way of communication. Politicians, for example, discover its visual possibilities to more easily reach voters and show their faces, increasing social presence [START_REF] Kaplan | Users of the world, unite! The challenges and opportunities of Social Media[END_REF]. Facebook introduced the Facebook live function in April 2016, to keep track on the growing competitiveness of other platforms in the field of image and video [START_REF] Zuckerberg | Facebook Mark Zuckerberg posts[END_REF]. YouTube channels of -mostly young -people, posting Vlogs about their everyday lives on the street in their neighbourhoods, provide opportunities to create new public figures in neighbourhoods. Furthermore, the development of video screens in public spaces is remarkable in this account. Veenstra [START_REF] Veenstra | Verbonden en verbindend. De openbare ruimte in de smart city[END_REF] shows the potential impact of using interactive displays in public spaces. Experiments of showing urban dashboards on public screens to create city services are promising in this regard.

Trend 4: Gamification and serious gaming

Today, an increasing number of games are designed for serious purposes [START_REF] Tan | The Evolution of City Gaming[END_REF]. There is an exponential growth in digital games in popular culture [START_REF] Kamel Boulos | From urban planning and emergency training to Pokémon Go[END_REF]. Serious games can be played in a wide variety of fields, often using simulations of real-world events, adopted with gaming characteristics. It is therefore providing players of a game with tools to gain more insights in fields of problems, mutual positions or even development tools [START_REF] Tan | The Evolution of City Gaming[END_REF][START_REF] Abt | Serious Games[END_REF][START_REF] Schouten | Games as Strong Concepts for City-Making[END_REF]. Gaming for the purpose of training, strategizing and learning is already widely accepted. A step further would be to see if gaming could even be working predictively and for policy-making. This is still on debate within scientific literature [START_REF] Tan | The Evolution of City Gaming[END_REF].

We saw that one of the important characteristics of urban media is time and place independency, given by the use of smartphones. The same trend is recognizable within the development of serious gaming for city development. These forms of urban media are the topic of various studies that aim to show the possibilities for enhancing citizen participation in area development.

Trend 5: Virtual and Augmented Reality

A variety of applications using both virtual and augmented reality is currently being developed. Several studies show the potential of using those techniques in the process of urban planning [START_REF] Zhang | The Usability of Online Geographic Virtual Reality for Urban Planning[END_REF]. The use of virtual worlds on mobile applications also proofed to be a suitable tool for stimulation citizen to participate in the process of urban planning [START_REF] Jutraz | Virtual Worlds as Support Tools for Public Engagement in Urban Design[END_REF]. Studies show a growing and wide variety of possibilities for the use of Virtual Reality Geographical Information Systems (VRGIS) and Augmented Reality Geographical Information Systems. All creating possibilities for smarter urban planning and citizen involvement in that process [START_REF] Kamel Boulos | From urban planning and emergency training to Pokémon Go[END_REF]. In 2016, the augmented reality game Pokémon Go showed an enormous impact on the use of public areas. This even led to prohibiting people to enter certain public areas for searching Pokémon [START_REF] Haag | De beste Pokémon Go-hotspots In Kijkduin[END_REF][START_REF] Haag | Pokémonspelers: houd Kijkduin schoon en leefbaar[END_REF].

Trend 6: New actors in area development

With the increase of smart city techniques, also new actors present themselves in the field of urban planning. Large scale area development, such as proposed by Google affiliated company Sidewalk labs in Toronto, are examples of such. Companies such as Cisco, IBM or Siemens that originate in sectors like ICT, Social Media or hardware development, now develop strategies for urban planning and city planning. Companies that do not have any rooted experience in these fields. Some experts in the field of urban planning consider this lack of historical awareness and knowledge on the process of urban planning, a dangerous development [START_REF] Hajer | Smart About Cities. Visualising the Challenge for 21st century urbanism[END_REF]. Especially since urban planning is considered a complex process [START_REF] Jutraz | Virtual Worlds as Support Tools for Public Engagement in Urban Design[END_REF]. Many of these actors tend to approach a city and urban development in a more rational way, almost comparable to the traditional approaches of urban planning that dictated the planning discourse in the first half of the twentieth century [START_REF] Alexander | After rationality[END_REF]. This has already led to criticism of the development of smart cities for being too technocratic and top-down in orientation. This could result in a structural neglecting of citizens interests and ignoring their needs [START_REF] Cardullo | Being a "citizen" in the smart city: Up and down the scaffold of smart citizen participation[END_REF][START_REF] Lange | Owning the city: New media and citizen engagement in urban design[END_REF][START_REF] Vanolo | Is there anybody out there? The place and role of citizens in tomorrow's smart cities[END_REF][START_REF] Shelton | The "actually existing smart city[END_REF][START_REF] Kitchin | Making sense of smart cities: addressing present shortcomings[END_REF]. Reactions of the companies in describing strategies towards more citizen-focused strategies, do not provide a more citizen-focused form of urban planning in smart cities [START_REF] Kitchin | Making sense of smart cities: addressing present shortcomings[END_REF].

Analysis of media for area development

We carefully analyzed the aforementioned trends in relation to the defined aspects of successful urban development in existing neighbourhoods. This analysis took place by developing a confrontation matrix where the trends were assessed on the found aspects of area development. The analysis resulted in either a potential positive effect, a potential negative effect, or no expected effect at all. While the analysis is not yet validated with large scale empirical data we encourage further research. The analysis is displayed in Table 2 and 3 and shows an overview of expected value based on theoretical and expert assumptions that were found in the research.

Table 2. Analysis trend 1-3.

Platform-society Citizen generated data Image and video

Own participation

Positive effect expected

No great influence expected

Positive effect expected

Platforms lower the barriers for citizens to participate New target groups can be reached through video platforms. These are low barrier options to participate.

Clear role of government

No great influence expected

Negative effect expected

No great influence expected Ethical dilemmas make the extensive use of data risky

Diversity

Negative effect expected

Positive effect expected Positive effect expected Because of the effect of filter bubbles on platforms, groups tend to develop in a homogenous way.

When using data analytics, data and opinions of every target group can be taken into account.

New target groups can be reached through video platforms.

Influence by minorities

Negative effect expected Positive effect expected Positive effect expected Because of the homogenous development, minorities can be in danger of not being heard.

When using data analytics, data and opinions of every target group can be taken into account.

New target groups can be reached through video platforms.

Table 3. Analysis trend 1-3 (continued)

Platform-society Citizen generated data Image and video

Widely set goals by government

No great influence expected

No great influence expected

No great influence expected

Room for experimentation

Positive effect expected

No great influence expected

No great influence expected Platforms provide an opportunity for exchanging ideas and improve experimental development.

Dynamics in society

Positive effect expected

Positive effect expected

No great influence expected.

Platforms provide opportunities to exchange ideas and benefit from energy in society.

Predictive analysis of data, can identify the dynamics of society.

Clear role of government

Positive effect expected

No great influence expected.

Negative effect expected

Role playing elements show clear division of roles.

In some cases, new actors make contracts with local governments. This could harm the needed transparency and clear choice of governmental role.

Diversity

Positive effect expected

No great influence expected.

Negative effect expected

Serious games can provide insights in opposing angles and show that target groups perhaps are forgotten.

The of lack insights and rooting in urban planning methods does not benefit the 'inefficient' use of diverse public. The lack of insights and rooting in urban planning methods does not benefit the 'inefficient' use of diverse public. This could be dangerous for the need of involving minorities.

Widely set goals by government

No great influence expected.

No great influence expected.

No great influence expected.

Room for experimentation

Positive effect expected

Positive effect expected

Negative effect expected

Serious games provide possibilities for experiments and test them in simulated situations.

VR and AR generate possibilities for showing the effect of experiments and adjust them endlessly.

The lack of insights and rooting in urban planning methods does not always fit to an experimental approach to urban planning.

Dynamics in society

Positive effect expected

Positive effect expected

Positive effect expected

Serious games thrive on enthusiasm. This functions better when acting on the dynamics of society.

VR and AR can generate enthusiasm by creating possibilities to envision endless number of possible future developments in neighbourhoods.

New actors often have a good antenna for finding the dynamics in society. This could benefit initiatives for neighbourhood development that thrives on these dynamics.

Discussion

It can be concluded that the six main trends we defined regarding the development of urban media, each show their own impact on citizen participation in urban planning. Some of the identified trends could even have a mutually amplifying effect, which makes the contribution of urban media even more significant to urban planning. The relatively new actors in urban planning that are rooted in the world of ICTs, gain lots of criticism in their technocratic role in the development of smart cities. Since they do not have a background in urban planning these new actors may have a negative impact on citizen involvement in urban planning.

Various limitations of our research have to be mentioned here. First, we focused completely on urban media trends that were identified from literature and experts. This means that we did not explore or revisited the body of knowledge regarding all kinds of earlier city participation technologies such as online forums, open data initiatives, web planning tools, cloud services and so on. A second limitation, raised here, is that our interviewees, that we considered as experts in this field, were exclusively from the Netherlands. This potentially limits the generalizability of the findings for other countries where the trends could not be that strong as in a country with the highest level of internet access. Urban media shows some remarkable opportunities for city planning in local neighbourhoods but has to be applied with care. The analysis in this article showed that some functions are better supported than others. And solely the existence of urban media does not solve the lack of interest in participation. Yet we have to find those specific configurations and strategies that enhance participation, based on hard work of people and creating valuable relationships. In that sense, urban media is maybe an old wine in a new barrel.

Table 4 .

 4 Analysis trend 4-6

		Serious gaming	VR/AR	New actors in area development
		Positive effect	No great	Negative effect expected
		expected	influence
		Serious gaming	expected.	New actors lack insights and root-
		stimulates par-		ing in urban planning methods.
	Own par-	ticipation of oth-		They can have a poorly developed
	ticipation	erwise less -in-		historical awareness. Often city
		terested target		development is approached in a ra-
		group		tionalised, technocratic manner.
				This does not support clear and
				'free' citizen participation.

Table 5 .

 5 Analysis trend4-6 (continued)

		Serious gaming	VR/AR	New actors in area dev.
		Positive effect	Positive effect ex-	Negative effect expected
		expected	pected
		Serious games	VR and AR gener-
		provide possi-	ate possibilities to
	Influence	bilities to gener-	show area develop-
	by minori-	ate insights in	ment through the
	ties	opposing an-	eyes of someone
		gles. Also it lifts	else. Therefor also
		support for op-	generating support
		posing views.	for minorities, like
			disabled people.

& AR Tech actors in urban field Interviewee 1 X Interviewee 2 X X Interviewee 3 X X X Interviewee 4 X X Interviewee 5 X X Interviewee 6 X X X X Interviewee 7 X X Interviewee 8 X


Aggeliki Androutsopoulou

Yannis Charalabidis
email: yannisx@aegean.gr

Euripidis Loukis
email: eloukis@aegean.gr

Policy Informatics in the Social Media Era: Analyzing Opinions for Policy Making

Keywords: Policy Informatics, Social Media, E-participation, Crowdsourcing, Citizen-Sourcing, Expert-sourcing, Maturity Model

In order to address the complexity of the modern social problems and needs through effective public policies, government agencies have started experimenting with policy informatics methods, adopting various approaches that increase citizens' and stakeholders' participation in the public policy formulation processes. Such approaches allow the exploitation of their opinions, which incorporate valuable perceptions of them, as well as knowledge, proposals and ideas. This paper outlines three advanced methods of social media (SM) exploitation in public policy making processes for citizen-sourcing, which are based on the concepts of active citizen-sourcing, passive citizen-sourcing and passive expertsourcing respectively, as well as the conclusions from some first applications of them. Based on them a comparison of these methods is conducted, and then a maturity model is developed concerning the use of SM for citizen-sourcing in order to support policy making.

Introduction

With our society becoming more and more heterogeneous and pluralistic in terms of culture, values, concerns and lifestyles, the social needs and problems become more complex and 'wicked', creating needs for new approaches in order to cope with them [START_REF] Head | Wicked Problems in Public Policy[END_REF][START_REF] Rittel | Dilemmas in a General Theory of Planning[END_REF]. These approaches necessitate government agencies to collect and process a large amount of external information concerning the different issues perceived by different problem stakeholder groups for the specific social problem under investigation, as well as the different solutions they propose and arguments in favor and against them, and in general their different concerns. Contemporary governments are responding to these challenges, by moving away from the 'elitist model' of public policy development, in which managers and experts are the basic source of policies, towards a new more 'democratic model', in which the citizens have an active role and voice as well in public policies' formulation. This has resulted into the adoption of the 'participative democracy' ideas, which are based on the extensive involvement of stakeholder groups in the formulation of public policies [START_REF] Rowe | Public Participation Methods: A Framework for Evaluation[END_REF][START_REF] Macpherson | The life and times of liberal democracy[END_REF]. In this landscape, policy informatics has emerged as a field studying how information and communication technologies (ICT) can be leveraged in order to understand better complex social problems and needs, develop public policies for addressing them, and realize innovations in governance processes and institutions [START_REF] Krishnamurthy | A glimpse into policy informatics: The case of participatory platforms that generate synthetic empathy[END_REF][START_REF] Dawes | Policy Informatics: Addressing Complex Problems with Rich Data, Computational Tools, and Stakeholder Engagement[END_REF]. Policy informatics uses modern computational methods to process vast quantities of data, mine data from single and multiple sources, seek patterns in multidimensional data, and develop models of various phenomena.

In parallel, the increasing availability of online user-generated content and the new ICT-based means of interactions between decision-makers and citizens has brought new potentials for collecting and analyzing citizens opinions, which incorporate valuable perceptions of them, as well as knowledge, proposals and ideas. Web 2.0 and Social Media (SM), constitute a 'paradigm shift in communication', which lowers the barriers of communication for individuals and groups, and brings new potentials to foster and support e-participation. This has led to the emergence of new opportunities for the 'policy informatics' field, based on approaches, methods and processes that incorporate Web 2.0 functionalities and architectures, and social networking tools, in combination with advanced text processing techniques for analyzing the huge amount of collected policy-related textual content. However, there is limited knowledge on how these ideas can be efficiently and effectively performed in the special context of the public sector, and supported by appropriate ICT platforms. This necessitates extensive research for the development of methods for the effective exploitation of SM in government, in combination with advanced text processing techniques, for supporting problem solving and policy making.

This paper makes a contribution in this direction, by outlining and comparing three advanced methods of SM exploitation in public policy making processes, developed as part of European projects, and synthesizing the results of their application and evaluation from various perspectives in order to develop new knowledge in the "Policy Informatics" area. Finally, based on our conclusions a maturity model is developed concerning the exploitation of SM by government agencies for policy oriented citizen-sourcing.

The paper is structured in six sections. In the following section 2 the background of our research is presented. Then, the three SM exploitation methods and their underlying ICT platforms are briefly presented in section 3, while their pilot applications are outlined in section 4. A comparison of the proposed methods is presented in section 5. Finally, in section 6 the conclusions are summarised.

Background

The great potential of the 'collective intelligence', defined as a 'form of universally distributed intelligence, constantly enhanced, coordinated in real time, and resulting in the effective mobilization of skills' [START_REF] Lévy | Collective Intelligence: Mankind's Emerging World in Cyberspace[END_REF], to contribute to difficult problem solving and design activities has triggered the interest in the adoption of crowdsourcing in the public sector. While many government organizations do not explicitly use the term, they increasingly attempt to use crowdsourcing ideas and practices in order to encourage collective problem solving in co-operation with external stakeholders (e.g. citizens, professional and sectoral associations, etc.). However, much less research has been conducted on the application of crowdsourcing in the public sector, focusing mainly on 'citizen-sourcing', than for the private sector crowdsourcing [START_REF] Linders | From e-government to we-government: Defining a typology for citizen coproduction in the age of social media[END_REF][START_REF] Nam | Suggesting frameworks of citizen-sourcing via Government 2.0[END_REF][START_REF] Prpić | The fundamentals of policy crowdsourcing[END_REF]. Citizen-sourcing can lead to the application of open innovation ideas in the public sector, as it changes government's perspective from viewing citizens as "users and choosers" of government services to "makers and shapers" of them.

The first citizen-sourcing initiatives aimed at the collection of policy-related information, knowledge and ideas from the general public, in order to support the development of better, more effective and acceptable public policies. So most of the initial government citizen-sourcing research is focusing on the 'active citizen-sourcing' paradigm, which uses government agencies' web-sites or social media accounts in order to pose 'actively' a particular social problem or public policy (existing or under development), and solicit relevant information, knowledge, opinions and ideas from the citizens (the general public) [START_REF] Mergel | Implementing Open Innovation in the Public Sector: The Case of Challenge. gov[END_REF][START_REF] Wandhöfer | Engaging Politicians with Citizens on Social Networking Sites: The WeGov Toolbox[END_REF].

Later, there has been research interest in the 'passive citizen-sourcing' paradigm, which aims to exploit 'passively' policy-related content that has been generated by citizens freely, without any direct stimulation or direction by government, in various external (i.e. not belonging to government agencies) web-sites or social media, such as political fora, news web-sites, political blogs, Facebook, Twitter, etc. accounts; the analysis of this content can provide useful information, knowledge and ideas concerning important social problems and public policies [START_REF] Charalabidis | Passive crowdsourcing in government using social media[END_REF][START_REF] Loukis | Promoting open innovation in the public sector through social media monitoring[END_REF][START_REF] Bekkers | Social media monitoring: Responsive governance in the shadow of surveillance[END_REF].

The assessment of the first citizen-sourcing initiatives revealed that they can provide useful insights about the perceptions of the general public concerning important societal problems and existing or prospective public polices for addressing them. However, they concluded that due to the high complexity of modern social problems and needs that had to be addressed through effective public policies, it would be highly beneficial if this general public oriented citizen-sourcing could be combined the collection of information, knowledge and ideas from experts as well. This lead to the emergence of the 'expert-sourcing' paradigm, which is in line with previous political sciences research on the role and importance of both 'democracy' (democratic processes and consultation with stakeholder groups) and 'technocracy' (specialized knowledge of experts) for the development of effective public policies [START_REF] Brown | Science in democracy: Expertise, institutions, and representation[END_REF][START_REF] Esmark | Maybe it is time to rediscover technocracy? An old framework for a new analysis of administrative reforms in the governance era[END_REF].

However, these different types of citizen-sourcing and expert-sourcing practices, aiming at the collection and analysis of public policy related information, public opinion, knowledge and ideas from experts' and citizens' communities, constitute innovations in the Policy Informatics field, and there is limited knowledge concerning their advantages, disadvantages and application in policy formulation processes in general. So, extensive further research is required in this area, in order to improve existing and develop new citizen-sourcing and expert-sourcing paradigms. The following sections outline some research that has been conducted in this direction, and attempt to synthesize their findings.

Three SM-based Citizen-sourcing Methods

For reasons of completeness of this paper, the three following subsections provide an outline of three SM-based methods that have been developed as part of European projects: an active citizen-sourcing method (3.1), a passive citizen-sourcing method (3.2), and a passive expert-sourcing method (3.3). Also, in each subsection references are provided that describe in more detail the corresponding method.

An Active Citizen-sourcing Method

The first method aims to conduct centrally managed online consultations on public policies, or social problems/needs, which are defined by the organizer government agency (so it performs 'active' citizen-sourcing), in multiple accounts of it in various SM. A central ICT platform is used in order to initiate, manage and monitor a policy consultation in multiple SM accounts of a government: initially are publish relevant messages on them, which define the topic/question of the consultation (it can be a public policy, existing or under development, or a social problem/need), and then the citizens interact with these messages through their accounts in the underlying SM [START_REF] Charalabidis | Fostering social innovation through multiple social media combinations[END_REF][START_REF] Charalabidis | Participative Public Policy Making Through Multiple Social Media Platforms Utilization[END_REF]. Both messages/content posting in these multiple SM accounts and continuous retrieval of citizens interactions with them (e.g. comments, likes, shares, etc.) are performed in a automated manner using the API of these SM from the above central ICT platform, in which also processing of these interactions (using advanced text analysis techniques) and results presentation takes place. The results include advanced analytics, based on advanced processing of citizens' textual inputs (e.g. blog postings, comments, opinions, etc.) using text analysis and opinion mining techniques. In particular, the following tasks are performed: (i) sentiment analysis, which classifies opinionated texts (e.g. blog posts, comments) as expressing positive, negative or neutral opinions, as well as the overall sentiment of citizens' comments submitted within a policy consultation, and (ii) issues detection, which identifies specific issues frequently posed by the citizens. This advanced processing is used to discover the public stance on the various issues of a policy topic. Another sub-component performs simulation modelling (Decision Support Engine), having mainly two objectives: estimation of the outcomes of various citizens' proposals on the public policies under discussion, and also forecasting the future levels of citizens' interest in and awareness of these policies. This method has been developed as part of the PADGETS project (www.padgets.eu)

A Passive Citizen-sourcing Method

The 'passive citizen-sourcing' method aims to exploit the vast amount of citizens-generated content beyond the SM accounts of government agencies, in 'external' Web 2.0 sources (i.e. not owned by government agencies, such as various political blogs, newspaper discussion forums, etc.), in order to provide to governments a better understanding of public needs, wishes and perceptions of citizens, as well as ideas, to be taken into account in the policy making process [START_REF] Loukis | Promoting open innovation in the public sector through social media monitoring[END_REF][START_REF] Charalabidis | Passive crowdsourcing in government using social media[END_REF]. An ICT platform has been designed for supporting the application of this method within the NOMAD project (www.nomad.eu), which consists of services that: (i) create and maintain domain models, i.e. graphical representations incorporating the main entities-terms of the domain of government activity in which the specific policy aims to intervene (e.g. energy, education), as well as policy models incorporating the main elements of the public policies under investigation (policy modelling); (ii) then use such policy models in order to mine relevant citizen generated data from a variety of pre-defined online external sources (through crawling services), (iii) perform linguistic analysis of them to transform free text into a set of structured data, (iv) discover and extract main issues discussed, as well as arguments from free text (argument extraction), (v) perform sentiment analysis to classify text segments according to their "tone" (positive, neutral, negative), (vi) cluster arguments, based on calculated similarities, and present automatically-generated summaries (argument summarization), and (vii) visualize a structured view of citizens' opinions on a policy related topic (through word-clouds and other kinds of charts), providing insights on what about, how much and when citizens are discussing concerning this topic (visual analytics). In this approach government does not define topics/questions of consultations; it remains passive, and just 'listens' to what citizens discuss on a specific policy, and analyze the content they freely produce in order to extract relevant knowledge (so it performs 'passive' citizen-sourcing).

Passive Expert-Sourcing Method

This third method provides the main capabilities of the previous one (outlined in section 3.2), but combined with filtering of the retrieved content, based on creator's reputation (enabling a focus on more reliable content created by high reputation authors) as well relevance with our pre-defined topic of interest. In particular, it is a 'passive expertsourcing' method, based on the automated retrieval from multiple online sources at regular time intervals of information about experts on various policy related topics, as well as relevant online texts, documents and postings already published by such experts in multiple social media and web-sites. Data about individuals possessing high levels of knowledge, expertise and credibility in one or more predefined topics are collected and included in the corresponding database automatically, or even can be entered manually by interested individuals through self-registration. In addition, rankings of the expert profiles on one or more topics, based on their relevant expertise, through 'reputation scores' are calculated by a reputation management algorithm based on several criteria with different weights. Another component of the ICT platform supporting this method, crawls relevant documents (blog posts, social media content, online comments, word/pdf documents, web pages, etc.) concerning the above predefined topics of interest. These documents are associated with the most relevant policy topic and subtopics, and possibly linked to one or more authors of the above individual experts'. Next, for each document its quality is rated with respect to the above policy topic/subtopic(s) and undergoes sophisticated processing using text/opinion mining and sentiment classification techniques, in order to assess their sentiment (positive, negative or neutral). By storing the above data in a common database, enabling search of it by the users and visual presentation of the results, public policy stakeholders are able to identify useful expert knowledge on complex policy debates, i.e. the most reputable/credible experts or the most relevant documents on a specific topic A comprehensive description of this method is provided in [START_REF] Androutsopoulou | Passive Expert-Sourcing for Policy Making in the European Union[END_REF].

Applications

The proposed citizen-sourcing methods have been applied in real policy scenarios and evaluated through pilot applications organized in cooperation with governmental actors (government agencies, members of national and European parliaments, public officials, etc.) in order to identify their strengths, weaknesses, barriers, limitations, as well as appropriate improvements and adaptations that will favor their practical usefulness and integration in the policy making processes. In order to build multi-perspective frameworks for the evaluation of the proposed methods, we draw elements from previous research management science (concerning risks of crowdsourcing [START_REF] Sharma | Crowdsourcing Critical Success Factor Model Strategies to harness the collective intelligence of the crowd[END_REF][START_REF] Agafonovas | Value creation in innovations crowdsourcing[END_REF] and diffusion of innovation theory [START_REF] Rogers | Diffusion of innovations[END_REF]), political science (concerning wicked problems theory [START_REF] Rittel | Dilemmas in a General Theory of Planning[END_REF]), and IS research (TAM [START_REF] Davis | A technology acceptance model for empirically testing new enduser information systems: theory and results[END_REF]) (see [START_REF] Loukis | Promoting open innovation in the public sector through social media monitoring[END_REF], [START_REF] Ferro | Policy Making 2.0: From Theory to Practice[END_REF]- [START_REF] Loukis | Using Social Media for Government Passive Expert-Sourcing[END_REF] for more details). In order to combine the advantages of the qualitative and the quantitative techniques [START_REF] Ragin | Constructing social research: The unity and diversity of method[END_REF] we used mixed methods of data collection, i.e. focus-group discussions, one-to-one interviews, and surveys. The active citizen-sourcing method outlined in 3.1 has been evaluated through three pilot applications, in cooperation with members of the European Parliament. At the end of each pilot application the following data have been collected and analyzed: (i) Social Media Metrics as provided by the SM accounts of the consultation initiators and the Google analytics engine and (ii) textual input of the participants were retrieved and analyzed using the opinion mining capabilities of the ICT platform in order to extract the main topics mentioned and the corresponding sentiments. All textual inputs by citizens were examined in more detail, in order to be classified into issues/concerns, solutions/activities, advantages and disadvantages/barriers. Fig. 1 shows an example of such classification in one of the pilot applications.

Fig. 1. Examples from the textual input of citizens in one of the active citizen-sourcing pilot applications

From this evaluation it has been concluded that this active citizen-sourcing method enables interaction and consultation concerning specific social problems/needs and public policies with wider and more heterogeneous audiences than other alternatives used by government agencies for this purpose, in shorter time and at lower costs. Furthermore, it assists in the analysis and elaboration of the particular problem/policy under discussion, as the identification of a wide range of particular issues and dimensions perceived by the citizens with respect to, leveraging relevant collective knowledge and experience. However, the method seems to be less efficient in the generation of solutions and the facilitation of convergence among stakeholders' views.

With respect to the passive citizen-sourcing method outlined in 3.2 three pilot applications have been conducted, in co-operation with the Greek and the Austrian Parliament, and the European Academy of Allergy and Clinical Immunology (EAACI), on topics that reflect important current debates and interests of these organizations. In Fig. 2 we can see a visualization of the results derived in one of these pilot applications, concerning the energy policy.

Fig. 2. Results visualization of the "Energy" pilot application of the passive citizen-sourcing method

In particular, the upper left visualization provides a word cloud of the most frequently issues detected in the accumulated content concerning the energy policy, while the upper right visualization provides charts on the volume of textual content found that is relevant with specific elements of the constructed policy models entities explained in Section 3.2 (policy statements or arguments). Then, the visualization in the middle of Fig. 2 indicates example of text excerpts that have been found in the crawled Web 2.0 sources and characterized as positive or negative arguments by the opinion mining analysis (indicated with green or orange color respectively). Finally, the visualizations in the lower part of Fig. 2 indicate the overall sentiment distribution in the retrieved content, the distribution of the volume of content found per type of source, and the evolution of content over time.

From the evaluation of these pilot applications it has been concluded that this passive citizen-sourcing method can provide considerable support for public policy making, by enabling the low cost and fast assessment of citizens' feelings/attitudes concerning a prospective or existing policy, and also the identification of particular issues posed by the society concerning this policy. Furthermore, it allows to a lower extent the collection of proposals concerning possible problem solutions and policy interventions. However, this method has some inherent risks, associated: a) with the misuse of it for promoting individual interests (by reporting selectively only a sub-set of its results, which is in the desired and supported directions by specific stakeholders, and hiding some others); and b) with the possible intrusion into citizens' private sphere (so it is necessary to avoid content sources in which contributors perceive their postings and discussions as private). Critical success factor of this method is the selection of an extensive, diverse and representative set of high reliability and quality medial sources to be monitored. Finally, for the evaluation of the passive expert-sourcing method outlined in 3.3 three pilot applications of it have been conducted, concerning three important EU policy related topics agreed among the 'EU-Community' project partners: Innovation and Entrepreneurship, Energy Union and Future of the EU. In Fig. 3 we can see some typical results visualizations. In the upper part we can see the detailed information about a specific document retrieved on a policy of interest. This information includes the results from the sentiment classification provided by the opinion mining algorithm regarding its polarity and as well as ratings and comments on it as input provided by other users. The lower part of the figure also presents a visualization of the sentiment classification of all documents retrieved within the application on the topic "Innovation & Entrepreneurship", ordered by temporal order of their appearance.

Fig. 3. Results visualizations of the passive expert-sourcing method

From this evaluation has been concluded that this passive expert-sourcing method has high levels of usefulness for the collection of high quality information and knowledge concerning all main elements of important social problems that have to be addressed through public policies: particular issues, proposed actions/interventions, advantages and disadvantages of them. Therefore it can make a significant contribution, and more multi-dimensional than the other two abovementioned citizen-sourcing methods, towards addressing the fundamental difficulty of modern policy-making: highly complex and 'wicked' social problems to be addressed [START_REF] Head | Wicked Problems in Public Policy[END_REF][START_REF] Rittel | Dilemmas in a General Theory of Planning[END_REF], with many issues, proposed actions/ interventions, with each of them having various advantages as well as disadvantages, and also multiple stakeholder groups with differing views and perceptions about them. Furthermore, this method has medium to high levels of usefulness for identifying existing attitudes/sentiments in the society towards the above main elements of important social problems under discussion, as well as their time wise change.

Comparison of Citizen-sourcing Methods

In the following Table 1 we can see a detailed comparison among the three citizensourcing methods discussed in sections 3 and 4, taking into account the capabilities they provide, as well as the outcomes of their pilot applications. Part of the comparison criteria have been taken from the e-participation domain model proposed in [START_REF] Kalampokis | A domain model for eParticipation[END_REF].

The main differentiations of the proposed methods lie on the type of citizen-sourcing they perform (active or passive) and their targeted audience (citizens/general public or experts), while each of them also employs different but overlapping sets of technologies. All methods exploit multiple Web 2.0 SM simultaneously as content sources, in a centrally managed manner, based on a central ICT platform. The acquisition of data from them is automated by using their APIs, however for some of the selected data sources that didn't provided such APIs, the usage of specialized crawlers is essential. Then all methods make sophisticated processing of the collected content, in order to extract the most significant points from it, in order to reduce the 'information overload' of government decision makers and provide meaningful insights for the policy formulation process. For instance, they all employ opinion mining and sentiment analysis techniques in order to extract target groups' opinions from the collected SM content, as well as advanced visualized presentation of the results. However, in the case of the two passive citizen-sourcing methods the quantity of the accumulated content is much bigger than in the active citizen-sourcing ones, so much more sophisticated processing has to be performed. A major difference is that in the first two methods content analysis is conducted at an aggregated level, and not at individual author level, while, in the third method results are collected and presented on the basis of individuals recognized as experts. For this reason, the third method includes techniques of policy experts' profiling and reputation assessment and management, used for filtering collected content. With regard to their application models each method demands effort in different phases. In particular, the application of the passive citizen-sourcing method needs more extensive work in the initial preparation, where domain and policy models have to be built by policy makers and domain experts. On the other hand, the active citizen-sourcing needs content posting by policy makers and their associates (defining the question/ topic of the consultation, and providing some base information about it, e.g. relevant text, images, video, etc.); also, this SM consultation has to be advertised, both initially, and in the whole period it is active, in order to attract large groups of citizens. Finally, in the passive expert-sourcing method less effort is needed, which is mainly concentrated in the interpretation and filtering of the results.

In order to examine and compare the stages of policy making each of the proposed methods can be used for, we have used the model of policy-making lifecycle stages proposed in [START_REF] Macintosh | Characterizing E-Participation in Policy-Making[END_REF], which includes five stages: agenda setting, analysis, policy creation, policy implementation and monitoring. Since passive citizen-sourcing is an unstructured idea collection process, without any definition of a specific problem statement, it can be launched in the agenda setting in order to bring social problems or issues into the attention of governments and administrations. When the definition of the social problem is structured, and the targeted policy area is defined, active citizen-sourcing can be launched to trigger citizens' reactions on them and gather their perspectives. In the subsequent stages (the policy creation and implementation), expert-sourcing is more substantial, since expertise and specialized knowledge is essential for these stages. Finally, in the monitoring and evaluation stage it is crucial to convey citizens views on the implemented policies, therefore either passive or active citizen-sourcing methods (posing questions on particular aspects of the policies) can be employed.

The evaluation results have revealed the major advantages of 'passive' approaches over the 'active' ones: (i) they enable government agencies to access, retrieve and exploit much larger quantities of more diverse policy relevant content from a wide variety of social media sources of different political orientations; and (ii) this content already exists, so government agencies do not have to find ways to attract large numbers of citizens to participate in citizen-sourcing and generate new content

Conclusions

In the previous sections of this paper a set of different approaches and methods for the exploitation of SM in government for supporting public policy making have been presented. Therefore, it provides some interesting contributions, which can be useful to both researchers in the policy informatics domain and government practitioners dealing with the public policy making. The findings from this research indicate that all the above approaches can definitely contribute to the timely collection of citizens' and as well experts' knowledge about social problems/needs as well as actions/interventions/policies for addressing them, taking advantage of the continuously growing Web 2.0 SM. So, they constitute valuable tools that can increase the quality, quantity and diversity of public opinion integrated and taken into account in public policy making. In general, the results revealed that although there are a number of risks associated with the application of these approaches (e.g. credibility and quality of collection information, manipulation of crowd), they are in general considered as effective and efficient methods for reaching wider and more diverse audiences at lower cost. Furthermore, the proposed approaches allow overcoming the usual 'information overload' problems of the traditional approaches, as they incorporate advanced content processing techniques, which are capable of extracting the main points of the collected content.

Based on the evaluation and analysis of these three methods we can distinguish a maturity model concerning the use of for citizen-sourcing by government agencies order to support policy making. It includes the following five maturity stages: I. Set-up and manual operation of multiple SM accounts: In this initial stage a government agency sets-up accounts in the most popular SM (e.g. Facebook, Twitter, YouTube), and operates them manually: content concerning its current services, activities as well as policies (current and future) is posted manually in each SM account, while citizens comments are read by public servants, and then summarized, and conclusions are drawn from them and sent to the appropriate interested units. II. Centrally managed operation of multiple SM accounts: In this stage the posting of content on each particular topic is conducted from a central ICT platform automatically to all SM accounts of the government agency; this ICT platform also retrieves automatically citizens' interactions (e.g. likes, shares, comments) for each posting, and makes advanced processing of them to facilitate summarization and conclusion drawing. III. External SM accounts central monitoring: In this stage, in addition to the centralized operation of the SM accounts of the government agency, we proceed to centralized monitoring of 'external' SM accounts and Internet sources in general, which have high quality content of interest, related to its activities and competences: interesting content is automatically retrieved, and then undergoes advanced processing, in order to facilitate summarization, main points extraction, sense making and conclusion drawing. IV. External SM accounts monitoring with quality filtering: This stage combines the characteristics of the previous ones, with quality filtering of the collected policy related content, based on the reputation of the author or/and the sources, aiming to provide information, knowledge and opinions from highly knowledgeable experts, and promote a 'democracy -technocracy' balance [START_REF] Brown | Science in democracy: Expertise, institutions, and representation[END_REF][START_REF] Esmark | Maybe it is time to rediscover technocracy? An old framework for a new analysis of administrative reforms in the governance era[END_REF] in the formulation of public policies. V. Internal dissemination and consultation: This final stage includes the characteristics of the above stages II, III and IV, combined with ICT-based internal dissemination of the collected information, knowledge and opinions from the citizens' general public and the experts, and also internal consultation on them (e.g. through 'internal' SM); this facilitates collective sense making, assimilation, conclusions drawing, and better exploitation of them for taking action, making innovations and designing better policies.

It should be noted that the three SM-based citizen-sourcing methods are not mutually exclusive, but can be combined. Further research is required concerning the combination and 'interoperation' of different methods along the policy formulation stages for providing more substantial decision support to policy makers and social actors.

Table 1 .

 1 Comparison among the three methods for SM-based citizen-sourcing

			Active Citizen-	Passive Citizen-sourcing	Passive Expert-Sourcing
			sourcing
	Type	of	Active		Passive	Passive
	Crowdsourcing
	Target Groups		General Public	General Public	Experts
	Involved Actors		Policy Makers	Public sector employees	Policy Makers
			Elected Repre-	Elected	Representatives	Elected	Representatives
			sentatives (MPs)	(MPs)	(MPs)
					CSOs	CSOs
	Level of Participa-	E-engaging		E-empowering	E-empowering
	tion
	Stages in Policy	-Analysis		-Agenda Setting	-Analysis
	Making		-Monitoring	-Analysis	-Policy Creation
					-Policy Creation	-Policy Implementation
					-Monitoring
	Data Sources		Social Media	Social Media
			(Facebook		(Facebook	Blogs
			Twitter		Twitter	Websites
			YouTube		YouTube	(Institutions,	Media,
			Blogger)		Blogger	NGOs/associations)
					Google+)	Social Media Accounts
					Bing	(Twitter, LinkedIn)
					RSS	News sites
					Websites
					News sites
	Data Acquisition		Social	Media	Social Media APIs	Social Media APIs
	Methods		APIs		Crawlers	Crawlers
	Processing Meth-	Social	Media	Social Media Monitoring	Social Media Monitoring
	ods		Monitoring		Opinion Mining / Sentiment	Opinion Mining / Senti-
			Opinion Mining/	Analysis	ment Analysis
			Sentiment Analy-	Argument Extraction &	Topic Modelling
			sis		Summarisation	Reputation Management
			Dynamic Simula-	Policy Modelling	Policy Modelling
			tion		Visual Analytics	Collaboration Support
			Visualisation		Visualisation
	Rules of Engage-	Social Media In-	Textual Input	Textual Input
	ment		teractions			Documents
			Textual Input		Ratings