Designing accessible mobile web interfaces for visual disabled people

Designing accessible mobile web interfaces for visual disabled people

Van Rhijn, R.

Ridder, H. (mentor)
Melles, M. (mentor)

Industrial Design Engineering

Industrial Design

Master of Science Design for Interaction

2011-05-30

Project purpose The purpose of this project is to design a method which supports designers in creating accessible mobile web interfaces for visual disabled users. This will be done by formulating a set of design principles which describe the do’s and don’ts of accessible mobile web design. Background Visual disabled people cannot interact with mobile devices the way normal people do. Whether an interface is accessible or not depends on two factors. First of all, back-end software, such as magnification software and screenreaders, should be able to transcribe the information to and/or from the interface correctly. Secondly, the interface itself should be designed in such a way that the back-end software is able to transcribe its information. In other words: the interface and the back-end software should speak the same language. If either one of these factors does not meet the requirements, the user-interface interaction cannot function properly. This project is about the second factor, designing the accessibility of the interface itself. User research How should mobile web interfaces be designed in order to make them accessible to people with visual disabilities? Based on user research, the purpose of this section was to clarify who visually disabled people really are and how they interact with mobile web applications. Five visual disabled participants were personally interviewed and observed while working with several mobile web interfaces. They stated that mobile web accessibility is of significant importance to them because it greatly supports freedom and independence. Furthermore mobile web interfaces are mainly used for general orientation and managing travel schedules. In this manner apps are clearly preferred over websites due to the limited amount of information, the simple and consistent structure and the immediate access to the user’s target. Following from the results a set of design principles was formulated for accessible mobile web design. ‘Profound simplicity’ considers the simplicity of hierarchy and the limitation of information. ‘First impressions’ emphasizes that users should be able to read and control information as quick as possible. ‘Screenreader accessibility’ explains that screenreaders should be able to transcribe the information to blind users just like it is intended to sighted users. ‘Magnification accessibility’ accentuates the possibility to magnify the content in an effective way. ‘Substitute solutions for typing’ encourages designers to avoid typing solutions where possible in order to help visual disabled users spare energy. Finally, ‘Use your imagination’ encourages designers to gain understanding of the target group in order to design suitable solutions. Design To demonstrate the effect of the principles on the accessibility level a redesign of the main menu of the app ‘9292OV Pro’ was created. Prior to the design process, the original design was elaborately analysed in order to identify the accessibility benefits and problems. Subsequently a structural and a graphic redesign were created. In preparation of the accessibility test a prototype was developed in cooperation with the company. Accessibility test The prototype was tested in order to verify whether the design principles indeed increase the level of accessibility as intended. A test with five sight impaired and five blind users was set up to compare the accessibility level of the redesign with the original app. The test consisted of some tasks that were executed with both designs. The accessibility level of the designs was evaluated by means of a survey. The results were then analysed on a quantitative and a qualitative level. In general, the analysis has verified that the design principles have a large positive effect on the accessibility level for both sight impaired and blind users. Other than some explicit advantages that were established by the participants, some issues were as well identified considering hierarchy, magnification and substitute solutions for typing. Based on the findings the principles were evaluated and revised in order to optimise their effect on the accessibility level. Discussion Assuming that other mobile devices are supplied with appropriate back-end software in the future, the principles will be eligible for implementation in other industries as well. Other than smartphones, a number of examples are digital photo and video cameras, MP3 players, portable game consoles, tablet PC’s, portable navigation systems for pedestrians and health monitoring devices such as glucose meters. It is important to realize that the formulation of the principles is based on just one interface. Since each interface is unique, it is likely that with other interfaces additional insights can be gained that might be very valuable in completion to the current principles. For this reason the company was recommended to continue testing future interfaces on the level of accessibility.

visual disability
accessibility
interface

http://resolver.tudelft.nl/uuid:244e05c5-6f75-424f-8387-3ab395a75ae9

Campus only

Student theses

master thesis

(c) 2011 Van Rhijn, R.