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Dive into the research topics where Lex Stefan van Velsen is active.

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Featured researches published by Lex Stefan van Velsen.


Knowledge Engineering Review | 2008

User-centered evaluation of adaptive and adaptable systems: A literature review

Lex Stefan van Velsen; Thea van der Geest; R.F. Klaassen; M.F. Steehouder

Adaptive and adaptable systems provide tailored output to various users in various contexts. While adaptive systems base their output on implicit inferences, adaptable systems use explicitly provided information. Since the presentation or output of these systems is adapted, standard user-centered evaluation methods do not produce results that can be easily generalized. This calls for a reflection on the appropriateness of standard evaluation methods for user-centered evaluations of these systems. We have conducted a literature review to create an overview of the methods that have been used. When reviewing the empirical evaluation studies we have, among other things, focused on the variables measured and the implementation of results in the (re)design process. The goal of our review has been to compose a framework for user-centered evaluation. In the next phase of the project, we intend to test some of the most valid and feasible methods with an adaptive or adaptable system.


Government Information Quarterly | 2009

Requirements engineering for e-Government services: A citizen-centric approach and case study

Lex Stefan van Velsen; Thea van der Geest; Marc J. ter Hedde; Wijnand Derks

Throughout the last decade, user involvement in e-Government service design has been virtually non-existent. Over time, e-Government experts began to realize that these services would benefit from a citizen-centric requirements engineering approach which has led to a demand for such an approach for this particular field. This article presents a citizen-centric approach towards user requirements engineering for e-Government services. It utilizes interviews and citizen walkthroughs of low-fidelity prototypes. A case study of a social support portal illustrates the approach and shows the need for repeated citizen inquiry, as the implementation of user requirements in low-fidelity prototype design is not always accepted by prospective end-users.


BMC Medical Informatics and Decision Making | 2013

Why mobile health app overload drives us crazy, and how to restore the sanity

Lex Stefan van Velsen; Desirée Beaujean; Julia E.W.C. van Gemert-Pijnen

BackgroundSmartphones and tablet computers have become an integral part of our lives. One of their key features is the possibility of installing third-party apps. These apps can be very helpful for improving health and healthcare. However, medical professionals and citizens are currently being overloaded with health apps. Consequently, they will have difficulty with finding the right app, and information and features are fragmented over too many apps, thereby limiting their usefulness.DiscussionIn order to combat health app overload, suppliers of apps need to do three things. One, join the open source movement, so that a few apps can work as gateway to medical information by incorporating information from different sources. Two, standardize content, so that the information provided via apps is readable. And third, in order to prevent information overload from occurring within an app, content should be personalized towards an individual’s characteristics and context.SummarySuppliers of medical information and features need to join the open source movement and must make use of standardized medical information formats, in order to allow third parties to create valuable, mobile gateway apps. This can prevent the occurrence of health app overload. By going along in these trends, we can make health apps achieve the impact on healthcare quality and citizens’ health many of us envision.


JMIR Research Protocols | 2013

Designing eHealth that Matters via a Multidisciplinary Requirements Development Approach

Lex Stefan van Velsen; M.J. Wentzel; Julia E.W.C. van Gemert-Pijnen

Background Requirements development is a crucial part of eHealth design. It entails all the activities devoted to requirements identification, the communication of requirements to other developers, and their evaluation. Currently, a requirements development approach geared towards the specifics of the eHealth domain is lacking. This is likely to result in a mismatch between the developed technology and end user characteristics, physical surroundings, and the organizational context of use. It also makes it hard to judge the quality of eHealth design, since it makes it difficult to gear evaluations of eHealth to the main goals it is supposed to serve. Objective In order to facilitate the creation of eHealth that matters, we present a practical, multidisciplinary requirements development approach which is embedded in a holistic design approach for eHealth (the Center for eHealth Research roadmap) that incorporates both human-centered design and business modeling. Methods Our requirements development approach consists of five phases. In the first, preparatory, phase the project team is composed and the overall goal(s) of the eHealth intervention are decided upon. Second, primary end users and other stakeholders are identified by means of audience segmentation techniques and our stakeholder identification method. Third, the designated context of use is mapped and end users are profiled by means of requirements elicitation methods (eg, interviews, focus groups, or observations). Fourth, stakeholder values and eHealth intervention requirements are distilled from data transcripts, which leads to phase five, in which requirements are communicated to other developers using a requirements notation template we developed specifically for the context of eHealth technologies. Results The end result of our requirements development approach for eHealth interventions is a design document which includes functional and non-functional requirements, a list of stakeholder values, and end user profiles in the form of personas (fictitious end users, representative of a primary end user group). Conclusions The requirements development approach presented in this article enables eHealth developers to apply a systematic and multi-disciplinary approach towards the creation of requirements. The cooperation between health, engineering, and social sciences creates a situation in which a mismatch between design, end users, and the organizational context can be avoided. Furthermore, we suggest to evaluate eHealth on a feature-specific level in order to learn exactly why such a technology does or does not live up to its expectations.


Sensors | 2014

Optimal sensor placement for measuring physical activity with a 3D accelerometer

Simone Theresa Boerema; Lex Stefan van Velsen; Leendert Schaake; T.M. Tönis; Hermanus J. Hermens

Accelerometer-based activity monitors are popular for monitoring physical activity. In this study, we investigated optimal sensor placement for increasing the quality of studies that utilize accelerometer data to assess physical activity. We performed a two-staged study, focused on sensor location and type of mounting. Ten subjects walked at various walking speeds on a treadmill, performed a deskwork protocol, and walked on level ground, while simultaneously wearing five ProMove2 sensors with a snug fit on an elastic waist belt. We found that sensor location, type of activity, and their interaction-effect affected sensor output. The most lateral positions on the waist belt were the least sensitive for interference. The effect of mounting was explored, by making two subjects repeat the experimental protocol with sensors more loosely fitted to the elastic belt. The loose fit resulted in lower sensor output, except for the deskwork protocol, where output was higher. In order to increase the reliability and to reduce the variability of sensor output, researchers should place activity sensors on the most lateral position of a participants waist belt. If the sensor hampers free movement, it may be positioned slightly more forward on the belt. Finally, sensors should be fitted tightly to the body.


BMC Medical Informatics and Decision Making | 2014

Participatory eHealth development to support nurses in antimicrobial stewardship

Jobke Wentzel; Lex Stefan van Velsen; Maarten van Limburg; Nienke de Jong; Joyce Karreman; Ron Hendrix; Julia E.W.C. van Gemert-Pijnen

BackgroundAntimicrobial resistance poses a threat to patient safety worldwide. To stop antimicrobial resistance, Antimicrobial Stewardship Programs (ASPs; programs for optimizing antimicrobial use), need to be implemented. Within these programs, nurses are important actors, as they put antimicrobial treatment into effect. To optimally support nurses in ASPs, they should have access to information that supports them in their preparation, administration and monitoring tasks. In addition, it should help them to detect possible risks or adverse events associated with antimicrobial therapy. In this formative study, we investigate how nurses’ can be supported in ASPs by means of an eHealth intervention that targets their information needs.MethodsWe applied a participatory development approach that involves iterative cycles in which health care workers, mostly nurses, participate. Focus groups, observations, prototype evaluations (via a card sort task and a scenario-based information searching task) and interviews are done with stakeholders (nurses, managers, pharmacist, and microbiologist) on two pulmonary wards of a 1000-bed teaching hospital.ResultsTo perform the complex antimicrobial-related tasks well, nurses need to consult various information sources on a myriad of occasions. In addition, the current information infrastructure is unsupportive of ASP-related tasks, mainly because information is not structured to match nurse tasks, is hard to find, out of date, and insufficiently supportive of awareness. Based our findings, we created a concept for a nurse information application. We attuned the application’s functionality, content, and structure to nurse work practice and tasks.ConclusionsBy applying a participatory development approach, we showed that task support is a basic need for nurses. Participatory development proved useful regarding several aspects. First, it allows for combining bottom-up needs (nurses’) and top-down legislations (medical protocols). Second, it enabled us to fragmentise and analyse tasks and to reduce and translate extensive information into task-oriented content. Third, this facilitated a tailored application to support awareness and enhance patient safety. Finally, the involvement of stakeholders created commitment and ownership, and helped to weigh needs from multiple perspectives.


Journal of Medical Internet Research | 2012

Should Health Organizations Use Web 2.0 Media in Times of an Infectious Disease Crisis? An In-depth Qualitative Study of Citizens' Information Behavior During an EHEC Outbreak

Lex Stefan van Velsen; Julia E.W.C. van Gemert-Pijnen; Desirée Beaujean; M.J. Wentzel; Jim E. van Steenbergen

Background Web 2.0 media (eg, Facebook, Wikipedia) are considered very valuable for communicating with citizens in times of crisis. However, in the case of infectious disease outbreaks, their value has not been determined empirically. In order to be able to take full advantage of Web 2.0 media in such a situation, the link between these media, citizens’ information behavior, and citizens’ information needs has to be investigated. Objective The goal of our study was to assess citizens’ Web 2.0 media use during an infectious disease outbreak and to determine which Web 2.0 medium is used for which goal. With this information, we wanted to formulate recommendations for health organizations that consider using Web 2.0 media as part of their communication strategy during an infectious disease outbreak. Methods A total of 18 student participants kept an information diary for 4 weeks during the 2011 enterohemorrhagic E. coli (EHEC) outbreak in Germany. Of them, 9 lived at the epicenter of the outbreak and 9 of them at some distance. The diaries were supplemented by a qualitative pre-survey (demographics) and postsurvey (questioning their satisfaction with information provision during the outbreak). Results The Internet appeared to be the most popular medium for passively receiving EHEC-related information, with news websites and websites of newspapers as the most consulted sources. Twitter was used for receiving information to a small degree, while Facebook played virtually no role. Participants indicated that they thought information posted on Twitter or Facebook was not reliable or was out of place. When actively seeking information, online newspapers and wikis were important sources. Several causes for (dis)satisfaction with information provision were uncovered: source credibility, contradicting messages, and a need for closure. Conclusions During an infectious disease outbreak, our small sample of students did not see social media (like Facebook and Twitter) as suitable or reliable sources for communicating information, but primarily viewed them as a tool for communicating with friends. Wikis, however, did fill several information needs, especially when citizens are actively searching for information. For many, source credibility is an important asset of information usefulness. Finally, we provide several general recommendations for communicating with citizens during an infectious disease outbreak.


Journal of Aging Research | 2015

A community-based, technology-supported health service for detecting and preventing frailty among older adults: a participatory design development process

Lex Stefan van Velsen; Maddalena Illario; Stephanie Jansen-Kosterink; Catherine Crola; Carolina Di Somma; Annamaria Colao; Miriam Marie Rosé Vollenbroek-Hutten

Frailty is a multifaceted condition that affects many older adults and marks decline on areas such as cognition, physical condition, and nutritional status. Frail individuals are at increased risk for the development of disability, dementia, and falls. There are hardly any health services that enable the identification of prefrail individuals and that focus on prevention of further functional decline. In this paper, we discuss the development of a community-based, technology-supported health service for detecting prefrailty and preventing frailty and further functional decline via participatory design with a wide range of stakeholders. The result is an innovative service model in which an online platform supports the integration of traditional services with novel, Information Communication Technology supported tools. This service is capable of supporting the different phases of screening and offers training services, by also integrating them with community-based services. The service model can be used as a basis for developing similar services within a wide range of healthcare systems. We present the service model, the general functioning of the technology platform, and the different ways in which screening for and prevention of frailty has been localized. Finally, we reflect on the added value of participatory design for creating such health services.


Interacting with Computers | 2009

Incorporating user motivations to design for video tagging

Lex Stefan van Velsen; Mark S. Melenhorst

User video tagging can enhance the indexing of large collections of videos, or can provide the basis for personalizing output. However, before the benefits of tagging can be reaped, users must be motivated to provide videos with tags. This article describes a two-stage study that aimed at collecting the most important motivations for users to tag video material. First, focus groups with internet users were held to elicit all possible motivations to tag videos on the internet. Next, 125 persons ranked these motivations for two cases via an online survey and responded to statements that assessed their acceptance of personalized output, based on their tags. Motivations related to indexing appear to be far more important for people than motivations related to socializing or communication. Furthermore, people were moderately positive about personalized output, based on their tags. Finally, important user barriers to tagging are discussed.


electronic government | 2008

Engineering User Requirements for e-Government Services: A Dutch Case Study

Lex Stefan van Velsen; Thea van der Geest; Marc J. ter Hedde; Wijnand Derks

E-Government services can be made more user-friendly by involving prospective users in the requirements engineering stage. In this paper, we present user requirements engineering activities for e-Government services, demonstrate their effectiveness by means of a case study, and reflect upon their use. We used a combination of interviews with clients and involved service employees, which resulted in a set of requirements covering the different needs of future users. The design based on these requirements was tested with fifteen potential end-users, using rapid prototyping and a citizen walkthrough. These sessions show that it is crucial to test user requirements with potential end-users to create an e-Service that successfully caters to clients, providing such things as personalization and interoperability in an e-Government setting.

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C. Huijs

University of Twente

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