Considerations of Efficiency and Mental Stress of Search Tasks on Websites by Blind Persons

We examined what kind of rating index was usable for verification of usability of websites for blind persons. The search time had a strong correlation with the NASA-TLX WWL scores. This would suggest a possibility to evaluate the usability by the search time. On the other hand, in respect of the accessibility check tool, its verification result had no correlation with NASA-TLX WWL scores, so it could not be used as a tool for verification of usability. We must develop a new usability check tool for blind persons. If we place functions with high usage frequency and high level of importance at a top of the website where a user can easily recognize them, it not only gives us a high level of visibility but also is effective for a blind person using voice output web browser as well.