Well we undertook a study of validity and reliability of WCAG 2.0 and found that an 80% target for agreement is not attainable, when audits are conducted without communication between evaluators. Even with experienced evaluators the error rate is relatively high; and further, untrained accessibility auditors -be they developers or quality testers from other domains- do much worse than this. Read the full published text via ACM Author-izer Open Access on the publications page.
‘Web pages judged on the classical dimension as being visually clean showed significant correlations with accessibility, suggesting that visual cleanness may be a suitable proxy measure for accessibility as far as people with visual impairments are concerned. Expressive designs and other aesthetic dimensions showed no such correlation, however, demonstrating that an expressive or aesthetically pleasing Web design is not a barrier to accessibility.’