Isabella Scandurra
email: isabella.scandurra@it.uu.se

Jesper Holgersson
email: jesper.holgersson@his.se

Thomas Lind
email: thomas.lind@it.uu.se

Gunilla Myreteg
email: gunilla.myreteg@fek.uu.se

Development of Novel eHealth Services for Citizen Use -Current System Engineering vs. Best Practice in HCI

Keywords: user participation, public e-health services, e-government, electronic health records, system development methods, collaborative design, Scrum

Many new public eHealth Services are now being developed. Often a conventional customer-vendor process is used, where the customer is a public authority, e.g. a county council, and the vendor a commercial actor, e.g. an IT development company. In this case study the engineering process regards a novel eHealth service aiming to provide patients with online access to their electronic health record. A complicating factor in conventional customervendor processes for public e-services is that "the future user could be anyone". In the light of best practice in Human-Computer Interaction, this study examines the joint effort of the customer and vendor when developing novel services for citizen use. The results include delimiting factors, recommendations for public authority customers and proposed new actions for the research agenda.

Introduction

In present study, health information is brought to the citizen via online public eHealth services on home-or mobile devices. One expectation of public eHealth services in general is to make patients more involved in their own health and empowered in their relationship with caregiver organizations [START_REF] Atzori | SUSTAINS User Requirements Recommendations[END_REF]. Consequently, many new eHealth services with the aim to provide citizens with health information are currently being developed in Western Europe by both public healthcare providers and industry. One example is to provide patients with online access to their own electronic health record (EHR). Such a service can be seen as a public e-service which is a part of the egovernment imperative. To date, main goals with e-government have been to reduce costs and time needed to provide services to citizens [START_REF] Anthopoulos | Applying participatory design and collaboration in digital public services for discivering and re-designing e-Government services[END_REF]. As a result, public e-services have mainly been developed from an internal government perspective, and external user considerations have been given little attention [START_REF] Axelsson | Exploring the importance of citizen participation and involvement in e-government projects -practice, incentives and organization[END_REF]. Studies show that neither public authorities nor citizens benefit from the introduction of such public e-services [START_REF] Anthopoulos | Applying participatory design and collaboration in digital public services for discivering and re-designing e-Government services[END_REF].

It is evident that increased knowledge of external user needs is essential for successful deployment of public e-services [START_REF] Melin | Talking to, not about, Entrepreneurs -Experiences of Public e-service Development in a Business Start Up Case[END_REF] and there is a growing interest for citizen centeredness when developing public e-services in both governmental strategic documents [START_REF]Commission of the European communities, i2010 eGovernment Action Plan: Accelerating eGovernment in Europe for the Benefit of All, C.o.t.E. communities[END_REF] as well as in research [START_REF] Axelsson | Exploring the importance of citizen participation and involvement in e-government projects -practice, incentives and organization[END_REF]. However, it must be noted that user participation in public e-service development is challenging to put into practice. Public e-service development most often has to deal with a heterogeneous target group, i.e. all citizens [START_REF] Henriksen | The diffusion of e-services in Danish municipalities[END_REF]. Furthermore, citizens cannot be obliged to participate; their participation is voluntary, and performed besides their ordinary duties. Finally, procurement legislation and slim customer-vendor processes hamper use of user-centered requirement analyses. Consequently, and also due to traditional patterns, the process to develop public eservices is often based on conventional system engineering where future users are not involved in the development process. Public eHealth services provide no exceptions.

Present study adheres to Cooperative design [START_REF] Schuler | Participatory Design Priciples and Practicies[END_REF][START_REF] Bardram | Scenario-based design of cooperative systems: Re-designing an hospital information system in Denmark[END_REF] as one of the Human-Computer Interaction (HCI) research theories that regards system development with user participation and that considers design a social process [START_REF] Greenbaum | Design at work: Cooperative design of computer systems[END_REF]. From research literature we know that usability aspects should be brought in early in the development process [START_REF] Greenbaum | Design at work: Cooperative design of computer systems[END_REF][START_REF] Constantine | Software for Use: A practical guide to the Essential Models and Methods of Usage-Centered Design[END_REF]. Previous research also presents several methods to engage users in the future, like role playing and future workshops [START_REF] Greenbaum | Design at work: Cooperative design of computer systems[END_REF][START_REF] Jungk | Future Workshops: How to create desirable futures[END_REF]. Other methods to bring future needs analysis into system development are iterative prototyping and scenario-based design [START_REF] Bardram | Scenario-based design of cooperative systems: Re-designing an hospital information system in Denmark[END_REF]. The latter is a well-used model in Participatory Design, also known as the Scandinavian tradition, developed since the 1970's. [START_REF] Schuler | Participatory Design Priciples and Practicies[END_REF] The degree of user participation may vary. Regardless of activation degree, in cooperative design developers and practitioners/users are seen as active cooperating partners aiming to reduce uncertainty and risk in development of novel systems where no detailed conception of exactly which future needs should be supported and in which way [START_REF] Greenbaum | Design at work: Cooperative design of computer systems[END_REF][START_REF] Jungk | Future Workshops: How to create desirable futures[END_REF]. Also in User-Centered Design (UCD) [START_REF] Norman | Cognitive engineering, in User-Centered System Design: New Perspectives on Human Computer Interaction[END_REF][START_REF] Gulliksen | Key principles for user-centred systems design[END_REF] active participation of users is preferred; there are however other methods and techniques to apply when potential end-users are not accessible, such as personas to shape future users [START_REF] Mulder | The User Is Always Right: A Practical Guide to Creating and Using Personas for the Web[END_REF], inspection methods to evaluate an interface [START_REF] Nielsen | Heuristic Evaluation, Usability Inspection Methods[END_REF] and use of representatives for real users [START_REF] Constantine | Software for Use: A practical guide to the Essential Models and Methods of Usage-Centered Design[END_REF][START_REF] Gulliksen | Key principles for user-centred systems design[END_REF][START_REF] Beyer | Contextual Design. Defining Customer-Centered Systems[END_REF]. In the light of best practice from the HCI domain, the purpose of this study was to investigate the actual development process of the customer and vendor when developing novel eHealth services for citizen use: How did customers from a county council and IT-developers from industry collaborate to jointly develop a public e-service for a third party, i.e. patients or citizens? To what extent were best practice-methods from HCI used in the development of this novel public eHealth service?

Methods and Materials

The studied project SUSTAINS 1 , is a European Union (EU) financed collaboration that aims to develop and deploy different regional eHealth services on 16 sites in 11 European countries by 2014. At the start of SUSTAINS in 2012, the majority of the partners had already initiated some development and results are now emerging. The County Council of Uppsala (LUL) in Sweden is coordinator of the EU-project and subject to this case study. The clinical eHealth services in LUL enable patients in the county to access and read their EHR, containing medical notes, drug prescriptions, medical lab results, diagnoses and referrals [START_REF] Atzori | SUSTAINS User Requirements Recommendations[END_REF]. Development of these public e-services was performed in 2011-12 in a customervendor setting. LUL (the customer) was the initiator of this development and owner of the resulting eHealth services. The IT Company (the vendor) engaged in development of the eHealth services at LUL had previously been assigned to develop some of the predecessors of this current version. In November 2012 the eHealth services were made available to all, approx. 200 000 patients within LUL, following a minor launch in August limited to LUL employees (also considered patients) for testing purposes. Recently (in March 2013) a national strategy decision was made to deploy LUL eHealth services nationally; to provide all Swedish citizens with online access to their EHRs. This fact increased the interest to further study how novel eHealth services reach a heterogeneous target group, spread over an entire country, of different ages, education, health status and interests to use the services or to participate in the development process.

The study: Research Team Evaluators and Methods

An action research project (DOME2 ) was created by 16 nationally spread researchers to perform independent studies with multidisciplinary perspectives on the SUSTAINS EU-project. The four authors are members of DOME and each with an expertise in research areas related to eHealth: health informatics & HCI (IS), egovernment & cooperative design (JH), IT & deployment processes (TL), organizational change & management control (GM).

When the research project was initiated (August 2012), the SUSTAINS project had already established a customer-vendor organization and current version of eHealth services was being developed. The selected data collection method was therefore to perform semi-structured interviews with SUSTAINS members from both sides. Three roles from the customer; project manager, project owner and medical advisor, were matched to the vendor's development manager and two usability experts. Six interviews explicitly regarding the development process (table 1) were recorded and followed up by complementary questions and answers by face-to-face contact, phone as well as e-mails containing project documentation, requirements and system overviews from the vendor. The recorded material was transcribed and analyzed by all four researchers using a content analysis model where the development process of the system was described according to the Systems Development Life Cycle (SDLC) [START_REF] Avison | Information Systems Development[END_REF]. This model describes the development process as constituted of three phases: initial; with various analyses, intermediary; system is realized, and finally; system is put to practice.

Results: Current System Engineering vs. Best Practice in HCI

The actual process of SUSTAINS development is compared to best practice methods and key principles in HCI and displayed in table 2. The initial phase (1) of SDLC concerns preliminary analyses, systems analyses, and requirements specifications (future users are identified and the project is defined with regard to its scope and expected outcome), the intermediate phase ( 2) deals with systems design and systems development (the system is realized), and the final phase (3) concerns integration, testing, installation and deployment (the system is put to practice).

) A type of "Knowledge in the head": customer representatives had previously studied pilot projects in Denmark, Estonia and the United States, as well as experiences of a predecessor of SUSTAINS, implemented at a private practice in LUL. These experiences were not systematically documented nor reported in the form of a systems analysis or similar. Future users were generally identified as inhabitants in the county. System specification existed in terms of an EU-consortium negotiation of a list of 12 features that should create the basis for the novel eHealth system. "Black box-approach": There were no specified goals other than realizing the features listed by the EU-consortium. The scope was defined in terms of planned launch date, first access in summer of 2012, and a final launch in autumn of 2012. Neither users, nor developers were actively involved in the initial analyses of the novel eHealth services. a) Identify main target groups for the intended service, b) categorize future users/most frequent users [START_REF] Greenbaum | Design at work: Cooperative design of computer systems[END_REF]. c) Analyze thoroughly potential users to elicit user requirements in terms of functionality and usability [START_REF] Schuler | Participatory Design Priciples and Practicies[END_REF][START_REF] Norman | Cognitive engineering, in User-Centered System Design: New Perspectives on Human Computer Interaction[END_REF]. d) Use requirements and project goals to steer development [START_REF] Greenbaum | Design at work: Cooperative design of computer systems[END_REF][START_REF] Constantine | Software for Use: A practical guide to the Essential Models and Methods of Usage-Centered Design[END_REF][START_REF] Jungk | Future Workshops: How to create desirable futures[END_REF][START_REF] Beyer | Contextual Design. Defining Customer-Centered Systems[END_REF] e) Stated goals and expected outcome are basic tools to create formative and summative evaluations [START_REF] Constantine | Software for Use: A practical guide to the Essential Models and Methods of Usage-Centered Design[END_REF][START_REF] Brender | Handbook of evaluation methods for Health Informatics[END_REF]. f) Participation of real users is preferred to decrease uncertainty and risks related to system acceptance, and a number of methods are presented in Introduction [START_REF] Schuler | Participatory Design Priciples and Practicies[END_REF][START_REF] Bardram | Scenario-based design of cooperative systems: Re-designing an hospital information system in Denmark[END_REF][START_REF] Greenbaum | Design at work: Cooperative design of computer systems[END_REF].

(2) Communicating mental models: The vendor's development team got involved and started by designing a prototype based on the 12 features. It needed to be redesigned with respect to a user perspective.. . Usability experts were called to assist; they performed a heuristic evaluation, a conceptual model and created 3 personas; an old demented woman and g) Actively involve future users in design activities. The degree of user participation may vary, h) from an advisory role as a part of design team [START_REF] Schuler | Participatory Design Priciples and Practicies[END_REF], using e.g. future workshops [START_REF] Jungk | Future Workshops: How to create desirable futures[END_REF] i) to a more representative role during testing, prototyping and similar user-centred Current system engineering process (Cont'd) her relatives, a disabled child and his parents, and a woman with multiple diagnoses. Results were delivered to the customer that accepted to rebuild the prototype. Changing requirements: The vendor used Scrum; an agile software development framework [START_REF] Cajander | Existing but not Explicit -The User Perspective in Scrum Projects in Practice[END_REF]. The development manager (i.e. scrum master) took the task to turn vague specifications into practically solvable requirements of the novel system. The Scrum process used iterations of three weeks, each ending with a customer demonstration using personas to get feedback for improvements and acceptance of each functionality. Users were not systematically incorporated in development activities but a focus group test day with patient organizations was a mandatory step in the EU-project. It is not clear whether/how this day was analyzed to improve the services. The vendor managed to simulate user participation when the customer assumed the role of user representative using each of the personas during demos.

Best practice in HCI (a selection of key principles)

activities [START_REF] Greenbaum | Design at work: Cooperative design of computer systems[END_REF][START_REF] Constantine | Software for Use: A practical guide to the Essential Models and Methods of Usage-Centered Design[END_REF][START_REF] Gulliksen | Key principles for user-centred systems design[END_REF][START_REF] Beyer | Contextual Design. Defining Customer-Centered Systems[END_REF]. j) use mock-ups [START_REF] Greenbaum | Design at work: Cooperative design of computer systems[END_REF] user scenarios and prototypes to trigger discussion around possible future technologies. k) Incremental development or iterative prototyping is advocated to gradually establish understanding between users and developers.

(l) When potential end-users are not accessible other UCD-methods like inspection methods with guidelines [START_REF] Nielsen | Heuristic Evaluation, Usability Inspection Methods[END_REF], user representatives or (m) personas [START_REF] Mulder | The User Is Always Right: A Practical Guide to Creating and Using Personas for the Web[END_REF] should be applied.

(3) Practice in practice Only a few tests were carried out by the customer. The launch in August 2012 giving access to employees in LUL was a nonsystematic test as each employee was free to use the system in the way she wanted. There was no systematic way of collecting reactions or questions from the users apart from a provided e-mail address as an option to feed back experiences. This option was sparsely used by the employees and no end-user education was provided. At service launch in November 2012, the same feedback system was used. n) Actively involve future users in evaluations and tests regarding GUIs as well as workflows and functionality [START_REF] Gulliksen | Key principles for user-centred systems design[END_REF] o) Active user participation in these stages increases the likelihood for successful deployment. If real users are not accessible, there are other formative and summative evaluations to perform; with or without usability experts [START_REF] Norman | Cognitive engineering, in User-Centered System Design: New Perspectives on Human Computer Interaction[END_REF][START_REF] Brender | Handbook of evaluation methods for Health Informatics[END_REF]. p) End-user education is important.

Discussion and Conclusion

The SUSTAINS case: Analysis of current case has shown that HCI best practice was not followed by the customer for any of the three phases. Overall, the project applied a scarce amount of user participation. "The users' needs were known to some extent by the aid of a survey conducted in 1999 and by the experiences made in the private general practice" (R2) Instead of an inventory among patients today, the customer (particularly the project owner) tried to take on the role of a future end-user based on the reasoning that it was future end users' needs which were of importance: "An average patient of today cannot know what she needs and demands from a future eHealth service system, as her views on and ideas of health and health systems will change, along with her own behavior". Moreover, no stated projector effect goals made development and evaluation difficult. The logic was, that "if a stated goal is invalid according to a future user it will not matter if the system can fulfill the goal or not". According to HCI best practice, that uncertainty can be decreased using different user centered methods and techniques.

The vendor was only involved in the intermediate phase of the project regarding development of the services from specifications provided by the customer. Fortunately, the customer was supported by the vendor in handling some end-user issues and the moving targets. Use of an agile development method brought the common understanding of expected results forward as the customer collaborated closely with the vendor's development team in frequent sprint demos. Further, an initial inspection evaluation led to redesign of the entire prototype as well as creation and use of three personas during development and sprint demos [START_REF] Cajander | Existing but not Explicit -The User Perspective in Scrum Projects in Practice[END_REF]. The usability aspects could be further refined, in many cases usability was neglected by the system's owner: "As far as I remember no one was responsible for usability aspects" (R5). "We have made no usability testing of the system" (R6) and currently "no one knows whether the eHealth services are useful or only an online service" (R5).

Recommendations to public authority customers: Although research has long advocated cooperative design methodologies, current public e-service projects are still technology-driven, instead of focusing on potential user needs. Use of existing and modified methods and techniques from the field of HCI as referenced here are of great value. In order to grasp this knowledge, it may be wise to incorporate HCI experts, not only from the vendor, but also internally, to establish a proper know-how of how to involve users to gain value out of the participation. In industry, usability experts are engaged in other projects, and only when called for their knowledge will be available for e-Government projects. It is therefore important to build in usage considerations early in planning and procurement documents, as well as working towards leaving conventional customer-vendor processes in favor of cooperative and agile methods. When HCI knowledge lacks at the customer end, which is not rare in healthcare, the developer must be given a mandate to handle these issues. In current case, the customer was led into development methods and processes selected by the vendor, in order to jointly develop a public e-service. In our opinion this project was saved by applying evolutionary prototyping, a thorough inspection evaluation and use of personas, where the customer meritoriously played user representatives using the 3 personas during iterative demos. However, working with future user-methodologies in a cooperative manner increases the likelihood for successful deployment according to best practice.

Proposed new actions for HCI research agenda: By this study we inform the HCI domain where practice really is standing, and we propose a call for action, to support public authorities/public care providers by leading them towards a collaborative and user-centered development environment in an action research setting.

Constructive evaluations of novel eHealth services need to be performed, not only usability tests in a user context in current project, but in all projects. HCI researchers could assist e.g. in a triple helix-constellation with public sector and industry to build e-services that meet future users' needs and possibly saving resources in the society.

Moreover, defined goals are needed. In this case e.g. how the system is intended to contribute to the patients' well-being, how or how much the system should ease the pressure on different services provided by healthcare today, or what impact the new eHealth services should have on the workload of certain clinical staff. Support from research in creating e.g. efficiency goals would benefit public e-service projects.

There is a need for educational projects to educate the customer to handle development processes with public user (citizen or patient)-centered perspectives. HCI researchers would also do well as mediators between customers, users and developers.

Neglecting future users and usability aspects is not unique for the studied project, on the contrary. There are recognized delimiting factors that e-government initiatives are associated with and that the HCI community could study and propose e.g. guidelines for. Compared to e-services developed by commercial actors, public e-services must encompass both economic and democratic values at the same time as public administrations are regulated by laws to a large extent [START_REF] Karlsson | Exploring user participation approaches in public e-service development[END_REF]. Being a public administration also brings the responsibility to provide e-services that provide clear benefit to the citizens since there is seldom an option to select another similar public e-service; they simply do not exist [START_REF] Lindgren | Electronic services in the public sector: A conceptual framework[END_REF]. At last, users of public e-services are citizens with certain constitutional rights. Public e-services cannot exclude any user groups although they are not a majority of the users, instead all future users must be considered, taking into account different disabilities, geographical limitation, and language issues [START_REF] Van Velsen | Requirements engineering for e-Government services: A citizen-centric approach and case study[END_REF]. These delimiting factors make user participation in public eHealth service development a challenging and complex activity and best-practice methods are needed to support public e-service development. Future work is to further examine which HCI methods, and to what extent HCI methods, can support the process of empowering patients and making them more involved in their own health.

Table 1 .

 1 Respondents from the customer-vendor organization of SUSTAINS.

	Respondents	Reference in text	Affiliation	Length of interview
	Project Manager	R1	Customer	60 min
	Project Owner	R2	Customer	120 min
	Medical Advisor	R3	Customer	90 min
	Development manager	R4	Vendor	90 min
	Usability expert 1	R5	Vendor	90 min
	Usability expert 2	R6	Vendor	60 min

Table 2 .

 2 Initial

[START_REF] Atzori | SUSTAINS User Requirements Recommendations[END_REF]

, intermediate

[START_REF] Anthopoulos | Applying participatory design and collaboration in digital public services for discivering and re-designing e-Government services[END_REF]

and final phase (3) of SUSTAINS and Best practice in HCI

Current system engineering process

Best practice in HCI (a selection of key principles)

SUSTAINS http://www.sustainsproject.eu/, retrieved

2013-05-15

http://www.it.uu.se/research/hci/dome/index.php?lang=1, retrieved 2013-05-15

Acknowledgments

The DOME-project is financed by VINNOVA (2012-02233), Swedish Agency for Innovation Systems. SUSTAINS is supported by the European commission (No 297206). Special thanks go to the respondents at LUL and the development company EVRY that invited us to a Triple helix environment for future work.


Frank Soboczenski

Paul Cairns
email: paul.cairns@york.ac.uk

Anna Cox
email: anna.cox@ucl.ac.uk

Increasing accuracy by decreasing presentation quality in transcription tasks

Keywords: Human error, cognition, data-entry, presentation quality, numberentry, infusion pump, perception, safety-critical systems

Many tasks with interfaces require entering data accurately, for example, entering patient data in an electronic records system or programming infusion pumps. However, human error is inevitable. Paradoxically, results from cognitive psychology suggest that representing information in a poorer quality format increases the likelihood of memorising the information accurately. This is explained by the dual system account of cognition where slower, more effortful but more accurate thinking is invoked via the poorer quality representation. We present two studies where we transfer these results to the domain of dataentry and show that poorer quality format of to-be-copied information leads to increased accuracy in transcription tasks. Moreover, this is not a consequence of the typical speed-accuracy tradeoffs. The results of our novel approach have implications for the design of data-entry tasks in domains such as healthcare.

Introduction

Routine data transcription tasks occur in a large number of settings, e.g. entering student marks into a spreadsheet, and paying bills via an online-banking system. But people are also prone to errors and while a wrong letter or number is sometimes little more than an inconvenience, things can get pretty ugly in safety-critical domains. One such domain, depending on a high standard of accuracy and data quality, is healthcare. For example, nurses are often required to enter large amounts of sensitive data in electronic health records (EHRs) and to program drug infusion pumps with information located on a prescription or infusion bag. A simple slip while transcribing patient data or programming a syringe pump in a hospital can quickly turn a routine task into a serious situation. Previous studies have shown that human errors are the source of more than 50% of incidents in most domains and in aviation can be as high as 90% [START_REF] Zhang | The Nature of Human Errors An Emerging Interdisciplinary Perspective[END_REF]. In healthcare the process of studying errors is only now emerging [START_REF] Wiseman | A Taxonomy of Number Entry Error[END_REF]. Recent studies have shown that people make transcription errors frequently and many systems do little to detect and prevent errors [START_REF] Thimbleby | Reducing number entry errors solving a widespread, serious problem[END_REF]. These issues strongly motivate our interest in reducing error rates in transcription tasks and we view this work as demonstrating an important new approach in this area.

Transcription tasks require users to perceive the target information, which is then coded into easily remembered parts in their memory. This is followed by the decomposition of the remembered chunks into separate characters to associate the matching keystroke to the relevant character. Once this association is complete, the individual characters are then translated into movements to press the proper key during the dataentry process [START_REF] Salthouse | Perceptual, cognitive, and motoric aspects of transcription typing[END_REF]. Previous research has shown that the ease with which a user can access the to-be-copied text impacts the strategies used to complete the tasks. So, how far away the to-be-copied content [START_REF] Back | Locked-out Investigating the Effectiveness of System Lockouts to Reduce Errors in Routine Tasks[END_REF] is or whether or not the user has to click to reveal it [START_REF] Gray | The soft constraints hypothesis: A rational analysis approach to resource allocation for interactive behavior[END_REF], can lead to differences in accuracy of performance. This is explained by the Soft Constraints Hypothesis [START_REF] Gray | The soft constraints hypothesis: A rational analysis approach to resource allocation for interactive behavior[END_REF], which suggests that people are more likely to use a potentially less accurate memory-intensive strategy over a more accurate perceptualmotor one when the cost of accessing information is higher. Gray et al. (ibid) demonstrate that memory-intensive strategies can lead to higher error rates in transcription tasks and therefore argue that reducing the effort required to access information can be beneficial.

Whilst much research has focused on decreasing the costs of accessing information, recent research has demonstrated that there may be disadvantages to this approach if the information processing strategy adopted is too passive [START_REF] Morgan | Designing Interfaces That Encourage a More Effortful Cognitive Strategy[END_REF]. Supporting evidence from [START_REF] Diemand-Yauman | Fortune favors the Bold (and the Italicized): Effects of disfluency on educational outcomes[END_REF] suggests that increasing the effort required to access information to be transcribed can be beneficial. Specifically, they argue that information represented in a less readable format can increase the likelihood of accurately memorising the information [START_REF] Diemand-Yauman | Fortune favors the Bold (and the Italicized): Effects of disfluency on educational outcomes[END_REF]. One explanation for this finding is that, in order to make sense of the text or the numbers, the user experiences cognitive dysfluency when reading and so moves away from more automatic reading processes towards more effortful processes [START_REF] Alter | Unity the tribes of fluency to form a metacognitive nation[END_REF]. Different names are used to describe these kinds of processes such as for example implicit and explicit [START_REF] Evans | In two minds dual-process accounts of reasoning[END_REF][START_REF] Reber | Implicit Learning and Tacit Knowledge[END_REF] and the more neutral, and increasingly common terms, System 1 vs. System 2 [START_REF] Stanovich | Individual differences in reasoning: Implications for the rationality debate[END_REF]. System 1 refers to automatic, hard to control, effortless and fast processes [START_REF] Kahneman | Explorations of the Mind Intuition[END_REF]. In contrast, System 2 is slow in execution, effortful and is limited in its capabilities [START_REF] Kahneman | Explorations of the Mind Intuition[END_REF]. Whether a System 1 or a System 2 process is chosen to complete a task is influenced by the task at hand. For example, when a calculation task changes from a relatively simple to a difficult task System 2 takes over. An example of such a scenario is thinking of tasks such as the question of what is the result of 2x2 or the question of what is the result of 342x319. In the latter example, System 2 takes control over the thinking process to produce an answer. The literature also presents an expansion of these well established thought processes by a third one namely System 3. This third process reflects on complex problem solving and prolonged major decisions, which take a very long time (i.e. months or years) and are therefore not applicable in this experimental context [START_REF] Dijksterhuis | System 3 thinking[END_REF].

There are also attempts in the literature to examine ways to stimulate increased cognitive engagement in certain situations. In one particular study [START_REF] Diemand-Yauman | Fortune favors the Bold (and the Italicized): Effects of disfluency on educational outcomes[END_REF], researchers tried to provoke people to think harder by manipulating the ease with which fonts could be read, and measuring the impact on the participants' ability to memorise specific information. Their results indicate that there is potential for great improvement in performance of people's memory when presenting information in a harder to read font.

In this paper, we present two studies to explore the effects of System 1 vs. System 2 on data transcription tasks. This is a novel application of results of [START_REF] Diemand-Yauman | Fortune favors the Bold (and the Italicized): Effects of disfluency on educational outcomes[END_REF], which are about memory, to the domain of interaction by which we might contribute to the findings of Gray et al [START_REF] Gray | The soft constraints hypothesis: A rational analysis approach to resource allocation for interactive behavior[END_REF]. In our first study we investigate the effects of dysfluency of text in the domain of text-entry. We chose text-entry as an initial study because it is widely known that number-entry studies produce a very low error presentation rate (usually below 5%) [START_REF] Oladimeji | Exploring Unlikely Errors using Video Games: An Example in Number Entry Research[END_REF][START_REF] Thimbleby | Reducing number entry errors solving a widespread, serious problem[END_REF]. As we are specifically looking for errors, a text-transcription task seemed ideal to simply get enough data to work with. The research instrument in the first experiment was the text-entry game TypoMadness, which we designed specifically for this purpose (see Fig. 2). Participants had to transcribe text phrases as quickly and as accurately as possible in two different conditions Clear & Obscured. In the second study, we transferred the results from text-directly to number-entry, comparable to the tasks in a healthcare environment. The task for participants in the second study was to re-enter given numbers in a calculator style interface i.e. serial interface in three different conditions Clear, Medium and Obscured.

Text-Entry experiment

At first pass, it appears intuitive that text that is less easy to read (illegible or dysfluent text) would result in a higher number of errors in a text-transcription task as a user may be more likely to misperceive the text. However, evidence from [START_REF] Diemand-Yauman | Fortune favors the Bold (and the Italicized): Effects of disfluency on educational outcomes[END_REF] & [START_REF] Morgan | Designing Interfaces That Encourage a More Effortful Cognitive Strategy[END_REF] suggests that dysfluent text could encourage the adoption of an alternative information processing strategy, resulting in fewer errors. The hypothesis for this study was that people would make fewer errors and therefore archive a higher score in the Obscured condition than in the Clear condition.

Participants

20 participants (9 men) with a mean age of 27.2 years (st.dev = 8.5) and mostly students at the University of Anonymous were randomly recruited by email as well as personal invitation. Nine participants stated that the task was difficult. However, only four of these nine people were part of the Obscured group. Moreover, these four participants further stated other reasons such as being unable to use the backspace-key than the visibility of the given text as the reason why they felt the task was difficult.

None of the participants had dyslexia or any other disability related to vision and reading. Additionally, all of the participants stated that they had normal or corrected to normal vision.

Design

A between-subjects design was used with ten participants in each group. The independent variable is the grade of visibility of the text. There were two conditions: Clear, which used clear visible content, (font-colour; #000000) and Obscured, which used less clear i.e. less visible content (font-colour: #BABABA) (see Fig. 1). The dependent variable was the score. It is the accumulated sum of correct entered characters in each task reduced by errors. An error in this study is anything that is not identical to the target text. This could be an additional space, upper or lower case difference, wrong or missing letters generally any sign different from the displayed text. Due to limitations of space, we have not reported an analysis by error type (slip, mistake etc.) in this paper. The set of 26 text phrases was counterbalanced across the study to avoid ordering effects.

Materials

The task was framed as a game in which the aim was to enter as many sentences as accurately and as quickly as possible within 15 minutes. Each sentence had between 95 and 161 characters and was displayed in either Clear or Obscured format. Additionally, the sentences were not connected in prose or any other form, so participants could not have predicted them. The sentences were randomly chosen from news and boulevard press websites such as theguardian.co.uk or cnn.com.

The game used for this study was implemented as a website in PHP with JavaScript. The website was connected to a MySQL database allowing the entered text phrases to be stored in the database for each participant. The displayed score was calculated out of the matching characters of each submitted text phrase. Each score for individual text phrases was stored in the database and displayed via cookies on the game website. The game website consisted of a display area in the centre of the page where the text paragraphs were displayed, a textbox for typing the text and a red button to submit the entered text and continue with the next task. The backspace button and the cursor keys were disabled in the text field so that participant could not change their entered text. All entered sentences no matter what they might be were saved in the database after a participant pressed the red button. The entered sentences were saved as a string in the database and compared to the original text. If there was any difference the score for that task was modified accordingly. It should be noted that where an error arose due to inserting an extra character, this did not cause all subsequent characters to be classed as erroneous.

The game was played on a MacBook Pro with a UK English keyboard layout and a 13'' size display at 1280x800 resolution. The browser used for the experiment was Google Chrome running under Apple Mac OSX 10.7.5 (Lion). The game website ran in the browser, the browser window was maximised and controls were disabled from being shown so that only the game itself was visible. All other applications were closed. In addition, there was also an informed consent to sign at the beginning of the study and a brief paper-based demographic questionnaire to fill out by participants after they completed the main task. The demographic questionnaire was used to specify the participants but not further used in the analysis reported here. A smartphone was used to stop the time by the experimenter.

Procedure

After reading the instructions, participants completed two training sentences, which were separate from the main sentence set of the experiment. The target text was presented in a textbox in the centre of the individual webpage. After the participants finished entering the training session a new start page was displayed only with a start button. Participants could see their score (in form of a character count as seen in Fig. 2) displayed on the right side of the text field. On completion of the training, the participant proceeded to the main study by clicking on the start button.

The target text was presented either Clear or Obscured depending on the condition. Participants were instructed to enter the target text as quickly and as accurately as possible. In order to get the highest possible score, all tasks had to be completed within 15 minutes though participants were not shown how long they had been playing. The experimental design in form of a game made it necessary to put participants under some form of time-pressure. This was also done as means of increasing the error rate. Each time the participant pressed the red button, their score was updated though there was no direct indication of any errors. If they completed the task within the 15 minutes, the final pages displayed the overall score. The experimenter controlled the smartphone and stopped the participant at the end of the given time limit. After finishing the entry task, the experimenter offered each participant a small break before asking the participants to fill out a demographic questionnaire. The participants were then debriefed as to the goals of the study.

Results

The hypothesis for this study was that there would be significantly fewer errors in the Obscured group (i.e. a higher score) than in the Clear group. The mean of the errors made in the Clear group was 830.1 (sd = 516.3) whereas in the Obscured group was 360.4 (sd = 127.0). The spread of errors is much higher in the Clear group than in the Obscured group (see Fig. 3). A Mann-Whitney-W test was conducted, as error data does not follow a normal distribution, which revealed a significant difference between the two groups (W = 23, p = 0.04). Furthermore, though we had a directional hypothesis, a more acceptable twotailed test was chosen to avoid the controversies around one-tailed testing [START_REF] Abelson | Statistics as principled argument[END_REF]. This move also resulted in a higher threshold for significance and therefore would give us more confidence in our findings.

In terms of speed of completing the task (see Fig. 4), the mean rate for entering sentences for the Clear group was 1.69 sentences/min (sd = 0.45) and for the Obscured condition 2.02 sentences/min (sd = 0.49). There was no significant difference in the rate of entering sentences (W = 26, p = 0.07). Moreover, the participants in the Clear group entered a mean of 23.1 (sd = 2.99) sentences and the in the Obscured group 25.0 (sd = 1.63). A boxplot illustrates the sentences entered by group (see Fig. 5). There were also no significant differences between the number of sentences participants completed (W = 32, p = 0.15). Four participants from the Clear group and seven participants from the Obscured group managed to enter all the 26 given text phrases and finished ahead of time. This leaves six participants from the Clear and three from the Obscured group who could not finish in time and therefore used the full 15 minutes.

Discussion

As predicted, the results showed that participants in the Obscured group achieved higher accuracy scores (i.e. fewer errors) than those in the Clear group. One explanation for this reduction in errors could be a speed accuracy trade-off. However there was no significant difference between the two conditions in neither the rate of enter-ing sentences or on the total number of sentences entered by each group. Indeed, the participants in the Obscured group entered more sentences, working at a faster rate suggesting that the reduced readability of the font was not slowing the participants down. Nonetheless, they made fewer errors than the Clear group.

Our manipulation is identical to that of [START_REF] Diemand-Yauman | Fortune favors the Bold (and the Italicized): Effects of disfluency on educational outcomes[END_REF] who suggest that increasing the effort required to access information results in an increase in the likelihood of accurately memorising the information [START_REF] Diemand-Yauman | Fortune favors the Bold (and the Italicized): Effects of disfluency on educational outcomes[END_REF]. However, we only focussed on representing the tobe-entered information in a faded font-colour but not also in a different font-style, which indicates a more robust outcome. The results therefore suggest that a more memory intensive strategy may have been adopted by the participants in the Obscured group which, in this case, resulted in enhanced performance.

Focusing on limitations, it can be argued that the size of our sample (20 participants) is simply too small to have confidence in our data. This might be true and requires further studies to get a more robust set of data, which is one reason why we decided to present a second study on the effect of System 1 and System 2 in this paper. On the other hand a larger sample size might just present a larger effect of our detected result as we have chosen to examine our data with a higher threshold of significance (two-tailed test). An improved experimental design would suggest to use sentences, which are all of the same length to avoid possible control confounds. Additionally, grey text can be more legible than black text under specific circumstances, depending on the level of contrast with its background and the overall level of luminance. Some types of dyslexia respond well to contrast reduction for improving readability. However, there were no dyslexic participants (at least not that they were aware of) in our study. Additionally, prior experience in data-entry work of participants ore even any prior knowledge of the material might have influenced their performance in our task; therefore a more careful selection of participants for future studies needs to be considered. Moreover, there is also the argument that a too high grade of obscurity of text may result in participants getting frustrated or suffer from fatigue and therefore abandon the task. We regard this as major issue and designed our next study to explore performance across a range of levels of obscured information.

Number-Entry experiment

As the results from our initial text-entry study were very promising we were keen on exploring the discovered effect of System 1 vs. System 2 in number-entry. Therefore, we directly transferred the task from text-to number-entry in the next experiment. The hypothesis for our second experiment was that there is a significant difference in the number of errors between the conditions Clear, Medium and Obscured.

Pilot

The reason why the number-entry study consists of three conditions resulted out of an initial pilot study among 53 first-year undergraduate students in computer science. This pilot to measure the effect of System 1 vs. System 2 in the domain of numberentry was designed accordingly to the previous text-entry experiment with two conditions Clear and Obscured to measure a significant difference in the amount of errors between these two groups. We discovered that participants did make more errors in the Clear condition but not significantly more errors. We also noted that our initial design of our Obscured condition was too strong i.e. the obscured numbers were too faded, which made it too hard to read for participants. It was then decided to design this study with three conditions to explore a wider range of different levels of obscurity. These three conditions were all less obscure than in the pilot study. The participants of this pilot study were not allowed to take part in the described follow-up study.

Participants

Participants were randomly recruited by personal invitation or by email. There were 30 participants (16 men) with a mean age of 26.5 years (st.dev = 8.2) in total. Participants were mostly familiar with a calculator based number-entry interface as used in the study but none of them had previous experience of working in the healthcare sector. However, three participants stated that they were familiar with infusion pumps. Two people stated that they found the task difficult (one in the Clear and one in the Obscured group) and two different participants stated that they did not consider themselves to have normal vision (also one in the Clear and one in the Obscured group).

Five participants had never used a number pad before, 7 rarely used it, 14 sometimes used it and only 4 participants (one each in group Clear and Obscured and two in group Medium) often use a number pad to enter numbers.

Design

A between-subjects (3 groups) design was used with 10 participants in each group. The independent variable is the grade of visibility of the presented numbers and the textbox where participants enter the numbers. There were three conditions: Clear, which used clear visible content (font-colour; #000000), Medium (font-colour; #BDBDBD) and Obscured (font-colour: #DFDFDF), which used less clear i.e. less visible (light-grey colour) content (see Fig. 7). The dependent variables were the total number of errors made, particularly the rate of errors and also the number of corrected errors in each group. A single error is counted when any number is entered other than the displayed number. Further, a corrected error is an error where participants noticed that they made an error and entered the number again. These errors were not added to the total number of errors. As previously, error type is not considered in our analysis.

3.4

Materials

The task set for participants was designed as a game in which the aim was to enter as many numbers as accurately and quickly possible in a calculator-based interface within 5 minutes. Compared to the first experiment a five-minute limit was chosen for this study as the pilot study showed that participants could transcribe content that consists of numbers considerably faster than text. The visual design of the serial i.e. calculator-based number-entry interface was carefully created after real world infusion pumps such as the Baxter © AS40A or the Graseby TM 3400 syringe pump (see Fig. 6). For the purpose of this study only the number pad of the infusion pumps with an Enter and a Clear key was replicated all other buttons of the original interface design were removed from the interface as they could have a possible unwanted effect on participants. The interface was implemented in PHP and JavaScript with a logging feature, which recorded all user interactions with the virtual device and wrote all interactions into a MySQL database. The interface provided thirteen functional buttons usable by the keyboard-only interaction (numpad).

The display itself consisted of 16 components. Three number displays (number to be entered, score and number input field), Enter and Cancel buttons and 0-9 number buttons including the decimal key. By pressing the Enter key the current displayed number was saved and at the same time the display was cleared. The display itself provided participants to enter a 5-digit number with two digits after a separating decimal point as previously gathered numbers from infusion pump logs confirmed the validity of this number range [START_REF] Wiseman | A Taxonomy of Number Entry Error[END_REF]. There were three versions of the interface used in the study. One where the number to be entered was displayed with a normal font-colour (black on white background) (group Clear), one where the number was displayed with a slightly lesser visible fontcolour (light-grey on white background i.e. #BDBDBD) and the last one where the number to be entered was displayed in a hard to read faded font-colour (strong-faded grey on white background, i.e. #DFDFDF) in group Obscured.

In addition to the interface described above, which was accessed via logging into a website, the instructions as well as an informed consent document were printed out on paper for the participants to read and sign. Additionally, there was also a brief demographic questionnaire, which was implemented as a Google form. Again, this was not used in the analysis reported here.

The computer used was an Apple MacBook Pro 13" connected to an external keyboard and monitor with a 17" size display at 1920x1080 resolution. The browser used for the experiment was Mozilla Firefox 10 running under MacOSX 10.7.5 (Lion).

The interface ran in the browser, the browser window was maximised and controls were disabled from being shown so that only the interface area itself was visible. All other applications on the machine were closed and the auto-completion mode of the browser was deactivated. Furthermore, the keyboard was prepared so that participants could only use the numpad to enter numbers all other keys were disabled. Stickers were put in place on the '+' key to make it easier for the participants to associate the particular 'Clear' key function.

Each number a participant had to enter, whether it was for the training to get familiar with the controls or the main study, was randomly generated in the game and displayed in the left upper corner of the interface (see Fig. 7). A smartphone was also used for this study to stop the total duration each participant used to enter as many numbers as possible.

3.5

Procedure

After a participant had read the instructions, he or she was asked to become familiar with the use of the keyboard controls and the display of the interface. For this purpose they were asked to run 10 training trials, which were separate from the main experiment. Participants were asked to sit straight in front of the monitor to avoid a possible effect on the perception of the numbers as the Medium and Obscured information could be perceived differently from a different angle. After a participant became familiar of how the serial number-entry interface worked he or she was then asked to proceed to the main study. Randomly selected participants (first come first serve basis) were asked to enter the given numbers either in the Clear, Medium or Obscured group within 5 minutes as quickly and as accurately as possible. The experimenter stopped the participant at the end of the 5-minute timeframe. During the experiment participants themselves could not see how much time had passed. Each time a participant pressed the Enter-key the number he or she just entered which was shown in the centre display was saved to the database and a new number was instantly and randomly generated at the upper left display. Additionally, at the same time the numbers in both displays were compared and if they matched the score were increased by 100 points. Any other entry than the correct number resulted in a decreasing of the score by 50 points. After finishing the number-entry task, the experimenter offered each participant a small break. Each participant was then asked to fill out a small online demographic questionnaire and the participants were debriefed as to the goals of the study.

Results

The hypothesis for this experiment was that there is a significant difference in the number of errors between the three conditions Clear, Medium and Obscured. Participants entered in total 2391 numbers for all three groups (see Fig. 8), which resulted in 44 total errors (1.8%) and 149 corrected errors. 849 numbers were entered in group Clear (28 errors), 796 in group Medium (12 errors) and 746 in group Obscured (4 errors), respectively. The mean of the errors made in the Clear group was 2.8 (sd = 2.20) whereas in the Medium group was 1.2 (sd = 1.39) and in the Obscured group 0.4 (sd = 0.52). A Kruskal-Wallis test was conducted, as error data does not follow a normal distribution (see Fig. 9). The results showed a highly significant difference between the errors made in the three groups (H = 9.78; df = 2; p = 0.007). However, there was no significant difference in the total numbers entered between the groups (H = 2.08; df = 2; p = 0.35) (see Fig. 8) and the number of corrected errors (H = 0.23; df = 2; p = 0.89). The mean of the numbers entered in the Clear group was 84. Eleven participants (36%) made at least one error with only one person making no error in the Clear group, 4 persons making no error in the Medium group and 6 persons making no error in the Obscured group.

Discussion

Like the text-entry study the results showed that participants in the Medium and Obscured group achieved higher accuracy i.e. less errors than those in the Clear group. However, only the difference between Clear and Obscured is significant, which again suggests that the experimental manipulation similar to those suggested by the pilot has worked and there is a trend indicating that a more obscured representation of information can lead to less errors being made in data-transcription tasks. Still, as observed in the pilot a presentation of content that is too obscure might have the opposite effect of making numbers simply too hard to read and therefore resulting in people abandoning the task.

Nevertheless, the discovered result is not due to possible speed-accuracy tradeoffs. Yes, participants entered fewer numbers in the Obscured group than in the other groups however not significantly different. Interestingly, whilst the number of committed errors was fewer there is no difference in the number of the corrected errors. This may suggest that people use different strategies to correct errors or people are self-detecting their slip errors. While people who commit the errors think their action was correct, those who correct errors are aware of their mistakes suggesting that they are self-evaluating their actions on the fly. However, if people use a memory intensive strategy i.e. a strong encoding in memory then perhaps the corrected errors are made by comparison with memory rather than comparison with the original. It is interesting to note that there are fewer corrected errors, which also suggests different mechanisms behind corrected and uncorrected errors. Like other comparable studies [START_REF] Oladimeji | Exploring Unlikely Errors using Video Games: An Example in Number Entry Research[END_REF][START_REF] Thimbleby | Reducing number entry errors solving a widespread, serious problem[END_REF] the rate of number-entry errors is still low (1.8% in this case) but this does not mean it is less important to investigate why these errors happen. It is known that misprogrammed infusion pumps are the second most frequent cause of medication errors making it imperative to reduce as many errors as possible [START_REF] Smetzer | Preventing medication errors related to drug delivery devices[END_REF]. An error rate of 1.8% in medical device context can still result in grave consequences. And therefore, whilst the total number of errors is modest, there is still much to explore and to learn.

Overall discussion and Conclusions

We have presented two studies, which showed that less visible content could affect the information processing strategy adopted in a text-entry as well as in a numberentry task and, counter-intuitively, improved accuracy in the specific task.

This therefore suggests that less visible information can result less errors being committed in both text-and number-entry tasks. Moreover, the results show a strong support for the effect of System 1 vs. System 2 in the context of interaction. If tasks require a higher cost of access then evoking System 1 vs. System 2 might overcome the various problems presented by [START_REF] Gray | The soft constraints hypothesis: A rational analysis approach to resource allocation for interactive behavior[END_REF].

Further work employing eye-tracking measures is required to explore whether the information processing strategies adopted by those in the two groups result in differences in the number of fixations on, and the speed of reading of the target text. Specifically, it will be important to understand whether the enhanced performance of participants in the Obscured group is the result of slower more deliberate processes such as additional perceptual monitoring of the target text resulting in enhanced memory for the text or more careful execution of the motor movements required to enter the content. When focusing on design, our discovered results represent a potentially important contribution for the design of future medical devices.

However, there is the possibility that this effect will wear off over time. Future work will focus on a long-term study, where we can explore how long the discovered effect lasts in data-entry tasks.

Additionally, fatigue is another issue that needs to be examined in this context. There is evidence in the literature that, for example, nurses who are on extended work duty possess a significantly decreased level of vigilance [START_REF] Scott | Effects of Critical Care Nurses' Work Hours on Vigilance and Patients' Safety[END_REF]. The grade of frustration is another interesting aspect to explore. For example, if the visibility of the Obscured text is too low i.e. if the text is too hard to read then there is the potential that people will get too frustrated in entering numbers (or text) and simply lower their efforts towards a successful completion of the task or even abandon the task completely. In future studies, we are keen to consider how this effect can be applied further and explored to improve safety-critical systems such as infusion pumps.

Moreover, as healthcare personnel do not usually transcribe information from an electronic source but also from paper-based sources there is further room to explore the application of our findings in this context.

There is also the argument in the literature that text is processed differently in sense of string and individual characters [START_REF] Bradshaw | Three interrelated problems in reading: A review*[END_REF][START_REF] James | Letter processing in the visual system: Different activation patterns for single letters and strings[END_REF]. Additional work is required to explore the relations between these paradigms. For example, an alternative design for a textentry study could focus on using content in welsh-language and let participants reenter the text again in form of a game to investigate how people process text either in individual characters or as connected strings.

We believe our results revealed important findings based on a new approach to understanding the text-entry task. This may have significant implications for the design of tasks in safety-critical systems. We are therefore keen to continue to explore this seemingly fruitful research direction.

Fig. 1 .

 1 Fig. 1. Example of the text displayed in the Clear (upper) and Obscured (lower) conditions.

Fig. 2 .

 2 Fig. 2. The interface of the game TypoMadness.

Fig. 3 .

 3 Fig. 3. Boxplot of total number of errors made by all participants in each condition.

Fig. 4 .

 4 Fig. 4. Boxplot of the rate of typing (sentences/min) of participants in each condition.

Fig. 5 .

 5 Fig. 5. Boxplot of the number of sentences entered by each participant in each condition.

Fig. 6 .

 6 Fig. 6. Infusion pump models Baxter © (left) and Graseby TM (right).

Fig. 7 .

 7 Fig. 7. Experimental setup; serial interface in the Medium condition.

Fig. 8 .

 8 Fig. 8. Boxplot of amount of numbers entered by all participants in each condition.

  9 (st.dev = 5.45) whereas in the Medium group was 79.6 (st.dev = 13.95) and in the Obscured group 74.6 (st.dev = 17.61). Additionally, the mean of the corrected errors in the Clear group was 5.2 (st.dev = 5.18), whereas in the Medium group was 5.3 (st.dev = 6.80) and in the Obscured group 4.4 (st.dev = 3.59).

Fig. 9 .

 9 Fig. 9. Boxplot of the number of errors made by all participants in each condition.

Fig. 10 .

 10 Fig. 10. Boxplot of the error-rate of each participant in each group.


Paul Noble
email: paul.noble@cs.ucl.ac.uk

Ann Blandford
email: a.blandford@ucl.ac.uk

You Can't Touch This: potential perils of patient interaction with clinical medical devices

Keywords: Medical Devices, Safety, Resilience Engineering, Customisation

Clinical medical devices are designed with the explicit assumption that trained medical team members will operate them in appropriate hospital environments. As technological complexity increases, along with the possibility to create specific ward configurations, the potential for unusual interaction combinations poses challenges for safety and training. Resilience engineering proposes that a system should cope with disturbances and unexpected conditions. Consequently, an important consideration for design is to examine medical device interactions that can be considered 'non-routine'. In recognition of the localised nature of clinical practice, and in order to investigate the broad range and type of non-routine occurrences, a novel interview approach was adopted involving medical researchers and practitioners. Examples of nonroutine interaction were obtained across a diverse range of localities. Covert patient interactions and dangerous configuration combinations were identified which adversely affected treatment. Drawing on these concerns the potential role of patient involvement in bolstering system resilience is discussed.

Introduction

Any patient or visitor to a medical facility cannot fail to notice modern technological equipment situated in wards, departments, and operating theatres. These widely used interactive devices undergo natural technology cycles in which manufacturers drive advancement by demonstrating the limitations of yesterday's models, and market the latest feature sets. As a result, it is not uncommon for these devices to increasingly suffer from 'feature bloat', in which new and seldom-used functionality makes operation increasingly confused and complex. An advantage of this approach is that the same medical device can be used across many hospital departments, where specific functionalities are all accessible through the device interface. However, following an institutional drive for simplification, medical device manufacturers have provided the ability to adapt and configure aspects of the user interface; for instance to show or hide menu items, or to re-order procedural input steps and set default values. This permits device tailoring by hospital department and ward type. Human-computer interaction (HCI) has long concerned itself with the inadequacy of systems that fail to reflect working practice, and are inflexible in use. In particular, many ethnographic studies observing interactions 'in the wild' have emphasised frequently the unplanned and situated nature of technology use [START_REF] Suchman | Plans and Situated Actions[END_REF]. Medical devices operate within behaviourally complex and emergent environments, and the latest systems can simply relocate error by introducing as many new issues as existing problems that they are designed to solve [START_REF] Koppel | Role of computerized physician order entry systems in facilitating medication errors[END_REF]. In this regard, the opportunity for device configuration and tailoring poses a number of design decisions balancing safety, training, and efficiency.

Resilience engineering [START_REF] Hollnagel | Resilience Engineering: Concepts and Precepts[END_REF] offers an alternate perspective to that of traditional risk management, examining particular strategies and procedures adopted by those within a system to allow it to succeed. Of specific interest is how the system is prepared for, and reacts to, disturbances and unexpected events. This shift in thinking has contributed to a growing interest in the examination and identification of resilient strategies surrounding interaction within complex socio-technical systems.

Bearing in mind the highly localised nature of medical device use, the objective of this paper is to understand the clinical environment by examining unexpected events and disturbances, and acquire generalisable insights for design. To address this aim, the paper presents a study of these 'non-routine' interactions. We recognise that the phrase non-routine is not ideal, however we deemed it the best general descriptor which could convey the temporal, normal, and legal aspects of the following properties: atypical, infrequent, unapproved, unauthorised, and untrained. Initially, the goal was to discover the breadth of technological interactions within the local clinical environments that were described as non-routine by participants. Non-routine dimensions were then extracted from these examples in order to facilitate understanding of the tensions within this space. Secondly, a resilience engineering perspective was applied in order to uncover areas of system vulnerabilities and weaknesses.

In this paper, existing literature from the fields of resilience engineering, appropriation, customisation, and ethnomethodology are initially reviewed. Subsequently, the novel methodology used in the study is described where interviews with medical researchers and practitioners are conducted. Situated non-routine dimensions are then presented and selected examples discussed. The following section then discusses an identified system area with low resilience (brittleness), and discusses the potential for unsafe complications with customised devices. The paper concludes by arguing for patient centered care in device design and practice.

Previous Work

Health care quality assurance literature [START_REF] Lillrank | Standard, routine and non-routine processes in health care[END_REF] describes successful healthcare organisations as having a requirement to be both flexible and efficient in order to succeed. Lillrank suggests that this is achieved through a mix of standard, routine, and nonroutine process elements, where repetitive processes can be standardised, routine processes consisting of both repetition and variability can be executed in dissimilar ways, and non-routine processes can be considered so variable as to be chaotic. This definition of non-routine complements resilience engineering's argument that a system should handle disturbances and unexpected events. Sujan [START_REF] Sujan | Resilience as Individual Adaptation: Preliminary Analysis of a Hospital Dispensary[END_REF] describes a resilience observation study of a hospital dispensary where individual staff cope with nonroutine occurrences on a daily basis, prioritising tasks in order to anticipate and moderate further disturbances. It is the understanding of the dynamics and differences from mundane practice to those surrounding the extraordinary event that is important for the resilient design of medical devices.

Historically, the introduction of new technologies into a variety of work domains has often failed due to misconceptions about local working practice. No system is a perfect fit, and the way in which technologies are successfully adopted, adapted and incorporated into working practice is through the process of appropriation. Interactive technology can also allow some degree of customisation to better meet the needs of particular individuals and groups of users. Therefore, customisation refers to a process of technology ownership where the needs of the individual are balanced with those of the group. Appropriation 'concerns the adoption patterns of technology and the transformation of practice at a deeper level' [START_REF] Dourish | The Appropriation of Interactive Technologies: Some Lessons from Placeless Documents[END_REF], and differs from customisation in that there is a co-evolution [START_REF] Rogers | Exploring Obstacles: Integrating CSCW in Evolving Organizations[END_REF] between the fitting of the technology within current organisational structures, and with the adaptation of working practices to support collaboration around the new technology. Randell [START_REF] Randell | User customisation of medical devices: the reality and the possibilities[END_REF] examined appropriation and customisation within the intensive care unit (ICU), observing situations where technologies are molded into working practices and are made to work in the way that the nurses want them to work, and not as envisaged by the manufacturer. Importantly, there is a strong motivation to share information and develop a working practice around the technology. This is described also by Wenger [START_REF] Wenger | Communities of Practice: Learning, Meaning, and Identity[END_REF] as how an individual develops membership of a Community of Practice (CoP).

In this paper, a distinction will be made between non-routine incidences occurring due to local appropriations and customisations, and all others. This is primarily because departments and wards generally have very good reasons for behaving in a particular way, based upon a solid history of experience. To an individual observing outside the particular CoP however, the reasons for these behaviours can be unclear. In addition, local practices that are not generalisable are not of interest to this study.

Although much work and attention has focused on case studies where medical device interactions have led to undesirable outcomes, less research has been conducted on the analysis of situations where devices are used in a non-routine way but do not directly cause harm. System stability and quality of care may be impacted even though there is no perceived association with error. The underlying objective of this work is to analyse unusual socio-technical interactions in order to better understand how to support patient health care through technology. Prior research leaves much about resilient situated device use unanswered. In particular, there is little understanding of the experiences of those who are outside the CoP but who still interact with the situated device, and what the implications are for system resilience and patient safety.

Methodology

Resilient strategies along with appropriated and customised interactions can be considered non-routine, dependent upon the comprehension of those inside or outside the workgroup community. In order to investigate the breadth of these non-routine medical device interactions a novel interview approach involving medical researchers and practitioners was adopted. A meta-analysis of the experiences of situated researchers and clinicians was conducted, probing their findings and research, and reinterpreting them in a different way. To be clear, this does not simply imply that a literature review was undertaken; the experiences and observations of those who conducted research in particular clinical situations were directly sought.

7 academics and research associates (including 2 clinicians) on the CHI+MED medical project 1 were chosen as participants in order to allow access to a broad range of professional experiences. All academics had conducted a number of situated medical studies as prior work. To facilitate the collection of rich and varied examples, participants were left to decide for themselves what the term 'non-routine' implied. All were invited to prepare some examples of non-routine interaction that they had encountered prior to interview. The interview consisted of two parts where prepared examples of non-routine interaction were initially recounted, before examples and experiences contributed by other participants were shared. In this way, an increasingly rich collection of examples was progressively used to stimulate and sharpen discussion. Researchers were interviewed in ascending order of experience, and prior to clinicians in order to allow examples and interpretations to be challenged or endorsed by final practitioner interviews. Semi-structured interviews with participants lasted approximately one hour and were recorded and transcribed. Initially data was categorised and filtered to remove customisation and appropriation examples. A thematic analysis was then conducted in order to draw out and identify dimensions influencing non-routine interactions. The initial analytic goal was to broadly understand the dynamics of those within the clinical environment in their efforts to manage non-routine events. Subsequently, a resilience engineering perspective was applied in order to elicit design insights from generalisable examples of use.

Results

The participants together contributed 29 examples of non-routine device interaction. 12 examples described work practice appropriations or customisations, 7 described 'forced' situations where there was compelling motivation for interaction within a timeframe, 4 described situations where medical research interactions were conducted by medical staff and patients, 4 described interaction errors primarily due to gaps in knowledge and experience, and the remaining 2 are what we termed 'covert' patient interactions.

4.1

Understanding the Clinical Environment

Four main aspects influencing whether an interaction is considered routine or not were identified. In order to assist understanding these have been arranged on a diagram representing a space of potential clinical device interactions (Figure 1). The legality of the interaction examines formal procedures, where subsequent approval must be sought if none exist. Work practice ascertains if best and local work practice is being applied, or whether workarounds are being followed. The novelty of the situation considers the requirement for an entirely original solution, or if a close variation can be adopted. User training distinguishes between complete and essential system training. The fluid and temporal nature of each dimension should be noted.

Fig. 1. Space of potential clinical device interactions

From Figure 1 it is clear that non-routine interactions are only possible in the middle and outer rings, with systemic risk increasing as a function of radius. Any individual dimension has the potential to pull the system into a region of risk. This analysis highlighted a vital role played by those community members who gave approval for responses to non-routine interactions. Prompt approval is critical as to how such a system resiliently and legally operates in an unpredictable environment and functions by both providing a damping mechanism through the coordination of an appropriate response, and that of information distribution by disseminating awareness of a particular event. One participant's example described the use of a newly introduced portable heart monitor to provide visibility of a patient's condition during ward transfer:

On this occasion, the heart monitor failed to activate after charging and displayed a "BATT COND" message. After some experimentation, it was discovered that if the battery was removed and reinserted, the message cleared and the unit functioned once more. Subsequently it was realised that the heart monitors' rechargeable batteries are intended to be discarded after 50 charge cycles in order to guarantee safe operation. The ward does not have the resources to register every time the batteries are recharged, and it has now become practice to remove and reinsert the battery to reset the device when the event reoccurs. An analysis of this example using the identified non-routine dimensions highlighted that initially this was a completely novel situation and so no training could have reasonably been provided to tackle this event. However, a solution was found and the team muddled through. Approval was then given for the technically illegal procedure, and the workaround became (possibly bad but known) practice.

Covert Patient Interactions with Medical Devices

The majority of the examples of non-routine interactions contributed were appropriations and customisations. This is unsurprising considering that these processes are normal means of embedding a technology and tailoring for practice. Of the other examples, those that described interactions in which patients would covertly interact with their clinical device were of particular interest, due to their potential impact on working practices and system resilience. In this study, there were two main motivators for patient interaction with clinical medical devices; the desire for unrestricted doses of a controlled substance, and for relief from device alarm noise. These examples all involved infusion pumps; devices that intravenously pump medicinal fluids into a patient's circulatory system. Most modern infusion devices provide functionality in which the keypad panel can be locked out in order to restrict access 2 . A physical button located on the casing, or selected through the software menu screen typically activates this type of locking mechanism. Understandably, patients are motivated to attend to this activity, as described by Participant A:

'But some patients are also very wise to the fact that there is a keypad lock button...because they watch, and I always teach nurses that if you are going to put the keypad lock on don't make it obvious that you are looking for the button to press that's not in a standard place...and that the patient actually works out what you're doing. You can actually do it on this particular pump by just sort of putting your hand on the top and looking like you're holding the pump as you're doing everything else' Another strategy used by patients is to look up the device manuals online, and discover the default locking codes or physical locking locations [START_REF] Grissinger | A Patient's Wandering Eye and the Internet Can Lead to Pump Tampering[END_REF]. In these manuals, interactions to be prevented are variously described as 'unauthorised', 'tampering' and even 'malicious tampering'. This may seem a little harsh in the case of the patient who simply seeks relief from a constantly alarming device, however frequently resetting the device alarm can also temporarily shut off the pump with unintended consequences. Participant B:

'Nobody wants to be shut in a room with something that's persistently alarming. So the problem was that when they were rechecking the blood of this patient they discovered that clearly he couldn't have been having all of his therapy. The problem is that if its [the pump] not infusing at a certain rate then you are not getting the target dose within a certain time frame, so the concentration never reaches the critical In this case, the patient had been covertly resetting his alarm so frequently that in the average period that the pump was operating correctly, there was not enough time to build up a particular concentration of the infused drug in his bloodstream.

Looking up device manuals online can appear a responsible alternative for a patient to exercise in preference to device menu exploration. However, the potential consequences of looking up information online can be serious, because as we have discussed it is possible for different wards to have the same medical device but with appropriated and customised configurations. Participant C recalled an example emphasising the dangerous potential for the untrained interaction of a customised device by medical team members or patients: 'I remember with the volumetric [infusion] pump, the trainer he pointed out that the bolus function on the thing doesn't mean bolus, or the primer, I can't remember but there was a specific function that either said prime or bolus or whatever, and he just said it doesn't do that. Press this button for something else essentially. So I think that's more to do with how the engineers set up the pumps'

Irrespective of what the particular pump functionality technically does here, the pump has been configured in a non-standard manner where a standard and labelled functional button delivers a different operation.

Conclusions and Future Work

As interactive medical devices move towards an increasingly feature rich future, it is apparent that some means of interface simplification is necessary. This paper examined potential complications caused by the ability to configure and customise, where the removal of standardisation increases the opportunity for non-routine interaction. The dynamics of non-routine interaction in a clinical medical environment suggest that device customisation will increase the burden of localised training by experienced community members, and impact safety. However, these disadvantages come at the gain of efficiencies for community members, and if possible, a safe balance must be found. One particularly interesting result of this study is the identification of covert patient interactions. These covert interactions already incur safety consequences, but are made potentially riskier when customised devices are operated using standard manuals found online. Restriction of information as means to control [START_REF] Adams | Social empowerment and exclusion: A case study on digital libraries[END_REF] has now largely been circumvented by these manuals. Using the resilience engineering perspective as a lens to uncover the absence of resilience can be illuminating. Particular areas of concern are situations where humans are prevented from contributing to system resilience. According to Participant D: 'The patients aren't there to think about what's happening with their treatment that's the nurses job'. However, involving patients in their own treatment would appear to be a particularly resilient action. Considering the management of false medical device alarms, this has the possibility to free up significant amounts of nursing time, as well as enormously improving the wellbeing of the patient. The patient should be integrated into the workgroup community and be made aware of interaction implications. Device designers also need to recognise and anticipate cases of patient interaction. Resilient infusion pump designs such as that by proposed by Nemeth [START_REF] Nemeth | The Infusion Device as a Source of Healthcare Resilience[END_REF] offer visualisation of a complete cycle of a treatment, and would have prevented some of the issues discovered in this paper. Achieving a safe mix of device customisation and safety would appear to be a delicate balance, and future work will explore the deeper issues surrounding the situated tradeoffs incurred.

CHI+MED (Computer-Human Interaction for Medical Devices, EP/G059063/1) is an EPSRC-funded project to improve the safety of interactive (programmable) medical devices.