I have recently had to write a project report on Accessibility in eAssessment and am developing a journal paper about the same. Here are a few of the issues and my thoughts on them:
1. Most exams or tests are time limited and a standard accomodation for disabled students is to allow more time. It occurred to me that these time constrains are more to do with organisational planning than having intrisic value in the assessment itself.
2. Another standard accommodation, providing diagram descriptions, leads to a particular challenge in the assessment context. It is all to easy for such descriptions to simply give the answer away. So here accessibility is a pedagogic issue as well as a technical one.
3. Most availible codes of practice for accessibility in education cover the assessment issues, when such assessmentments are offered on-line, very poorly. The otherwise good QAA CoP from the UK is a case in point here.
For more information see my paper when published.