Understanding and Supporting Web Developers: Working Practices and Resources for the Creation and Evaluation of Accessible Websites David Mark Swallow Doctor of Philosophy University of York Computer Science November 2017 2 Abstract Web developers have a responsibility to develop websites that are accessible and usable by the broadest range of users, including people with disabilities. Despite numerous initiatives over the last two decades to support, encourage and compel developers to fulfil this responsibility, websites continue to exhibit persistent accessibility problems. This programme of research aimed to better understand the difficulties that developers face and to develop the necessary support for them to successfully integrate accessibility into their existing workflows. The first study systematically reviewed 397 web accessibility evaluation studies published over a 15-year period between 1999 and 2014. This showed a persistent occurrence of accessibility problems that does not appear to be improving. The second study followed a contextual design methodology to investigate the working practices of 13 professional developers. This showed how they are hindered, not by limited awareness or concern, but by a lack of knowledge and practical guidance on how to make websites accessible. To understand the nature of their confusion and uncertainty, the third study interviewed 26 professional developers and attempted to elicit their mental models of web accessibility. Their mental models were found to incorporate some, but not nearly enough, knowledge and awareness of accessibility and were based on a conceptual model that prioritises technical conformance over user experience. These findings were embodied in the design and implementation of an accessibility information resource, called WebAIR. The ease of use and effectiveness of WebAIR in supporting the creation and evaluation of accessible websites was evaluated in a series of four studies with both professional and novice developers under increasingly realistic experimental conditions. The resource was well received by participants in each study and, despite concerns over its viability within organisations that place little value on web accessibility, WebAIR was demonstrated to be a usable, pragmatic accessibility information resource. 3 4 Table of Contents Abstract........................................................................................................................ 3 Table of Contents ....................................................................................................... 5 List of Tables .............................................................................................................11 List of Figures ........................................................................................................... 15 Acknowledgements .................................................................................................. 17 Declarations .............................................................................................................. 19 Chapter 1. Introduction ...................................................................................... 21 1.1. This is for everyone ................................................................................................ 21 1.2. Diversity in disability ............................................................................................. 22 1.3. The value chain of accessible web development ................................................. 24 1.4. Guiding accessible web development .................................................................. 25 1.5. Research aims and objectives ............................................................................... 26 1.6. Research contributions .......................................................................................... 29 1.7. Thesis overview ...................................................................................................... 29 Chapter 2. Literature review ............................................................................... 31 2.1. Methods for determining web accessibility ......................................................... 31 2.1.1. Automated accessibility evaluation ........................................................................... 31 2.1.2. Manual accessibility inspection .................................................................................. 35 2.1.3. User evaluation of web accessibility .......................................................................... 38 2.2. A history of web accessibility initiatives .............................................................. 39 2.3. The impact of web accessibility initiatives .......................................................... 46 2.4. Attitudes and awareness towards web accessibility ............................................ 47 2.5. Influences on and barriers to web accessibility ................................................... 55 2.5.1. Societal foundations.................................................................................................... 58 2.5.2. Stakeholder perceptions ............................................................................................. 63 2.5.3. Web development ....................................................................................................... 65 2.6. Conclusions ............................................................................................................ 69 Chapter 3. A systematic review of web accessibility evaluation literature ...... 71 3.1. Introduction ........................................................................................................... 71 3.2. Method .................................................................................................................... 72 3.2.1. Research question ....................................................................................................... 72 3.2.2. Identifying and selecting the primary research studies ............................................ 73 5 3.2.3. Data extraction strategy .............................................................................................. 76 3.2.4. Conducting the review ................................................................................................ 78 3.2.5. Augmenting the review ............................................................................................... 80 3.3. Results..................................................................................................................... 81 3.3.1. Publication frequency.................................................................................................. 81 3.3.2. Evaluation frequency .................................................................................................. 81 3.3.3. Website and webpage sampling ................................................................................. 83 3.3.4. Website type and location ........................................................................................... 86 3.3.5. Evaluation methods and tools.................................................................................... 88 3.3.6. Accessibility guidelines, conformance levels, and metrics ....................................... 91 3.3.7. Presentation of results ................................................................................................. 95 3.3.8. Evaluation results ........................................................................................................ 96 3.4. Discussion ............................................................................................................ 101 3.5. Conclusions .......................................................................................................... 105 Chapter 4. A contextual inquiry of web developer working practices ...........107 4.1. Introduction.......................................................................................................... 107 4.2. Method .................................................................................................................. 108 4.2.1. Design ......................................................................................................................... 108 4.2.2. Participants ................................................................................................................. 109 4.2.3. Procedure ................................................................................................................... 111 4.2.4. Data preparation ........................................................................................................ 112 4.3. Results................................................................................................................... 115 4.3.1. Flow model ................................................................................................................ 115 4.3.2. Cultural model ........................................................................................................... 119 4.3.3. Physical model ........................................................................................................... 124 4.3.4. Sequence model ......................................................................................................... 126 4.3.5. Artefact model ..........................................................................................................