Improving Content Design on Mobile Devices to Reduce Situational Visual Impairments

  • Garreth Tigwell

Student thesis: Doctoral ThesisDoctor of Philosophy


Billions of mobile devices are used worldwide for a significant number of important tasks in our personal and professional lives. Unfortunately, mobile devices are prone to interaction challenges as a result of the changing contexts of use, resulting in the user experiencing a situational impairment. For example, when typing in a vehicle being driven over an uneven road, it is difficult to avoid incorrect key presses.

Situational visual impairments (SVIs) are one type of usability and accessibility challenge mobile device user's face (e.g., not being able to read and reply to an important email when outside under bright sunlight), which suggests that current mobile industry practices are insufficient for supporting designers when addressing SVIs.

However, there is little HCI research that provides a comprehensive understanding of SVIs through qualitative research. Considering that we primarily interact with mobile devices through the screen, it is arguably important to further research this area. Understanding the true context of SVIs will help to identify adequate solutions.

To address this, I recruited 174 participants for an online survey and 24 participants across Australia and Scotland for a two-week ecological momentary assessment to establish what factors contribute to SVIs experienced when using a mobile device. My findings revealed that SVIs are a complex phenomenon with several interacting factors. I introduce a mobile device SVI Context Model to conceptualise the problem. I identified that mobile content design was the most practical first step towards addressing SVIs.

Following this, I surveyed 43 mobile content designers and ran four follow-on interviews to identify how often SVIs were considered and how I could provide effective support. I found key similarities and differences between accessibility and designing to reduce SVIs. The participants requested guidelines, education, and digital design tools for improved SVI design support. I focused on identifying the necessary features and implementation for an SVI design tool that would support designers because this would have an immediate and positive influence on addressing SVIs.

Next, I surveyed 50 mobile app designers using an online survey to understand how mobile app interfaces are designed. I identified a wide variety of tools and practices used, and the participants also raised challenges for designing mobile app interfaces that had implications for users experiencing SVIs.

Using my new understanding of SVIs and the challenges mobile designers face, I ran two design workshops. The purpose of the first workshop was to generate ideas for SVI design tools that would fit within a typical designer's workflow. I then created high-fidelity prototypes to elicit more informed feedback in the second workshop.

To address the problem of insufficient support for designers, I present a set of recommendations for developing SVI design tools to support designers in creating mobile content that reduces SVIs in different contexts. The recommendations provide guidance on how to incorporate SVI design support into existing design software (e.g., Sketch) and future design software. Design software companies following my recommendations will lead to an improved set of tools for designers to expand mobile content designs to different contexts. The development and inclusion of these designs within mobile apps (e.g., allowing alternative modes such as for day or night) will provide users with more control in addressing SVIs through enhanced content design.
Date of Award2019
Original languageEnglish
SponsorsEngineering and Physical Sciences Research Council
SupervisorRachel Menzies (Supervisor) & David Flatla (Supervisor)


  • Human-Computer Interaction
  • HCI
  • Accessibility
  • Situationally-Induced Impairments and Disabilities
  • SIID
  • Situational impairment
  • Situational Visual Impairments
  • SVI
  • Mobile devices

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