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Exploring the impact of icon similarity on user performance

Al Nuwaiser, W. (2020). Exploring the impact of icon similarity on user performance. (Unpublished Doctoral thesis, City, University of London)


Modern mobile devices have relatively limited screen sizes and often use small icons in order to make effective use of screen space. Icons are visual elements that represent an underlying meaning or function. Icon designers must do their best to convey underlying meanings or functions using these small visual elements, but users may misinterpret the intended meaning of an icon. While previous research has studied how users interpret icons, the existing body of knowledge is surprisingly small. Previous research has investigated how users interpret icons based on characteristics such as visual complexity, concreteness, and semantic distance; however, researchers still do not fully understand what influences the success or failure of a user in interpreting icons or how the underlying interpretation process works.

The research presented in this thesis advances our understanding of how users interpret icons. It investigates how users make decisions regarding the meaning of an icon based on (1) seeing another icon that looks visually identical to it but has a different meaning (ambiguous icons) either before or after seeing the primary icon, (2) an icon’s similarity or dissimilarity to a known ‘target’ icon, and (3) the visual context in which an icon appears. To address these questions, one exploratory study (Study I) and two experimental studies (Study II and Study III) were conducted. Studies I and II were lab-based, while Study III was conducted online. Study I found that users’ ability to accurately interpret ambiguous icons is influenced by the order in which the icons are seen. These results are supported by qualitative data which show that users most frequently cite icon sequence as the reason for their interpretation of ambiguous icons. The second study showed a tendency for users’ viewing times to increase as the visual dissimilarity of the icons increases. Furthermore, users tend to be highly accurate when interpreting the meaning of icons that look the same and have exactly the same meaning, while their accuracy is low when interpreting visually dissimilar icons. The findings of the third study suggest that the visual context has the potential to help users interpret icons. This thesis makes several contributions to the literature: It shows that the level of similarity or dissimilarity between icons influences users’ performance and that the visual context may play a role in interpretation. Furthermore, it introduces a new method to determine the visual similarity or dissimilarity of icons. These findings have practical implications for the design of icons.

Publication Type: Thesis (Doctoral)
Subjects: Q Science > QA Mathematics > QA75 Electronic computers. Computer science
Departments: Doctoral Theses
School of Science & Technology > School of Science & Technology Doctoral Theses
School of Science & Technology > Computer Science > Human Computer Interaction Design
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