Cognitive walkthrough and heuristic evaluation for Web GIS usability and trust implications.
Presented at: Methods and techniques of use, user and usability research in geo-information processing and dissemination, London, UK.
A common characteristic of Web GIS is that they are mostly used by non-experts, which generates usability and trust implications. Both usability and trust are well-researched in Human-Computer Interaction (HCI) and studies suggest that usability can improve the perceived trustworthiness of online systems. Trust was never examined in Web GIS and thus it is unknown how trust perceptions are formed and what, if any, usability problems influence the perceived trustworthiness of these systems. Usability Testing and Heuristic Evaluation can reveal usability problems but do not explain which influence trust. On an attempt to answer this question, a Heuristic Evaluation (HE) and a Cognitive Walkthrough (CW) were applied using the Environment’s Agency “What’s In Your Back Yard” (WIYBY) website. Although both methods are based on experts’ evaluations and can not replace User Testing, when used together can provide designers with enough insight on cognitive and affective user aspects which influence trust perceptions. It is also believed that this preliminary evaluation can inform the design of additional HCI methods which allow the involvement of real users (e.g. designing tasks to reveal trust-related problems). HE is a popular and informal inspection method, where the evaluators judge the system based on usability principles (Nielsen, 1994). A modified list of Xerox Corporation heuristics was used for the evaluation of the overall User Interface and for the GIS component were used the GIS usability heuristics developed by Nivala et al. (2008). One limitation of HE is that focuses on popular usability problems and it does not take into consideration the cognitive and affective processing of the end user, which influence trust formations. To overcome this problem the method of Cognitive Walkthrough (CW), which simulates the users’ problem solving practices (Wharton et al., 1994), was further implemented. For the CW the evaluators were provided with two persona-based scenarios, designed based on WIYBY documentation for target user groups and trust-related elements were added in order to reflect the user needs’ and expectations. A list of questions to consider for each task was also provided, such as: What is the effect that the user will try to produce? Are there any elements which might decrease user’s trust perceptions? Also, for the implementation of both methods three GIS experts were recruited, with different levels of expertise in using the methods and they asked for each problem to provide a severity rating and also note whether the problem is trust-related or not. The CW allowed the evaluators to identify problems that were not captured by the HE, especially more identical trust-related problems. Although, the heuristics supported the identification of several problems, these do not fully incorporate specific to the application cognitive and affective interaction aspects that should be taken into consideration, as it was demonstrated using the trust example. Cognition and emotions influence the use of these systems and their usability and yet our understanding of these issues in Web GIS n is still very limited. Time and cost effective methods such CW, can improve our knowledge and subsequently lead to the development of Web GIS, which are not only usable and trustworthy but also provide the users with a better overall User Experience.
|Type:||Conference item (Presentation)|
|Title:||Cognitive walkthrough and heuristic evaluation for Web GIS usability and trust implications|
|Event:||Methods and techniques of use, user and usability research in geo-information processing and dissemination|
|Dates:||2010-04-13 - 2010-04-13|
|UCL classification:||UCL > School of BEAMS > Faculty of Engineering Science > Civil, Environmental and Geomatic Engineering|
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