Design Framework for Trustworthy User Interfaces

Abstract

This thesis studies the relationship between user interface (UI) design, microinteractions and perceived trustworthiness in software systems. The thesis combines a narrative literature review with an empirical user study. The literature review gathers together research from trust psychology, human-computer interaction (HCI) and UI design to identify the most critical elements and decisions in UI design that contribute to trust formation. Based on already established trust models, such as the work of Mayer et al. and Hancock et al. the review finds functionality, helpfulness, predictability, visual trust signals and trust reinforcement actions as the core aspects of trustworthy UI design.

Based on the literature review, the Trustworthy User Interface Design Framework (TUIDF) was created as a practical checklist for UI designers. To validate the framework, two mobile banking application prototypes were created using Figma Make, an artificial intelligence model made for UI design. The control prototype was designed using traditional UI design principles while the experiemental prototype was designed according to the TUIDF. Ten participants divided into two focus groups completed tasks to evaluate the prototypes with a questionnaire combining the STS and the System Usability Scale (SUS). The TUIDF-prototype scored higher on most dimensions that were measured, including purpose, process, visual appeal and general trust. This suggests that the framework can improve perceived trustworthiness. The findings show that UI design based on the TUIDF produces measurable improvements in user trust, although further validation with a larger sample size is required.