Department of Mathematics and Computer Science

Standardized subjective measures are widely used in Human-Computer Interaction to assess constructs such as usability, perceived effort, workload, and user experience. Examples include the System Usability Scale (SUS) and the Rating Scale Mental Effort (RSME). Although such instruments are usually validated with a particular response format, their presentation in digital studies can vary considerably.
A rating scale may, for example, be displayed horizontally or vertically, represented as a slider or as discrete response options, or use different placements of labels and anchors. Previous research suggests that such seemingly minor design decisions can influence responses. Studies have found differences between Likert scales and visual analogue scales, between sliders and other response widgets, and even between horizontal and vertical presentations of otherwise similar scales.
Recent HCI research has therefore begun to consider response widgets as part of the measurement process rather than merely a visual design choice. However, it remains unclear how changes in presentation affect established measures commonly used in HCI and whether the same effects occur across different types of subjective measures.
This thesis investigates whether the presentation and interaction format of standardized subjective measures systematically influences participants' responses. The goal is to develop an experimental setup in which different representations of the same measurement instruments can be compared while participants perform otherwise identical tasks.
Possible factors include horizontal versus vertical scale orientation, continuous sliders versus discrete response options, and different placements of verbal or numerical anchors. The thesis may additionally examine response time, response consistency, or perceived ease of answering.

Procedure

The thesis begins with a literature review on subjective rating scales, response formats, and questionnaire presentation in HCI and survey methodology.
Based on this literature, suitable measures and alternative visualization formats are selected. The student develops a controlled experimental setup in which participants perform standardized tasks and subsequently provide ratings using different representations of the same measures.
The collected data are analyzed to determine whether presentation format systematically affects the resulting ratings and measurement properties. The thesis is conducted in close collaboration with the research group, particularly during selection of measures, experimental design, and interpretation of the results.

References

    •    Brooke, J. (1996). SUS: A “quick and dirty” usability scale. In Usability Evaluation in Industry, 189–194.
    •    Farzand, H., Al Baiaty Suarez, D., Goodge, T., Macdonald, S. A., Marky, K., Khamis, M., & Cairns, P. (2024). Beyond Aesthetics: Evaluating Response Widgets for Reliability & Construct Validity of Scale Questionnaires. Extended Abstracts of the CHI Conference on Human Factors in Computing Systems (CHI EA '24). https://doi.org/10.1145/3613905.3650751
    •    Toepoel, V., & Funke, F. (2018). Sliders, visual analogue scales, or buttons: Influence of formats and scales in mobile and desktop surveys. Mathematical Population Studies, 25(2), 112–122. https://doi.org/10.1080/08898480.2018.1439245
    •    Weijters, B., Millet, K., & Cabooter, E. (2021). Extremity in horizontal and vertical Likert scale format responses: Some evidence on how visual distance between response categories influences extreme responding. International Journal of Research in Marketing, 38(1), 85–103. https://doi.org/10.1016/j.ijresmar.2020.04.002