If we were to comply with the WAI WCAG guidelines to this particular assessment it would have been necessary to amend the assessment to add ALT text to the images. However doing so would have changed the pedagogic purpose of the assessment and would not have tested that the students have acquired the stated learning outcomes.
An alternative to reCAPTCHA...still not perfect. It could trip up someone with cognitive disabilities..or pretty much anyone having an off day. But perhaps it's better than asking a blind user to remember an 8 digit sequence with JAWS talking over the recording and having to repeatedly enter/exit forms mode? It could be edited to include an easier sequence which would make it even more accessible for everyone except spambots.
I realy like some of what Plymouth State is doing to allow browsing by LC subject. If you click, for examle, Sociology, you are taken to a sort of socioloy portal that contains links to course guidelines, relevant databases, pre-populated searches of the OPAC, reference materials, websites, and the sociology librarian's contact info. Click on a pre-populated OPAC search and you are able to broaden/narrow the search by clicking tags as well as bookmark or choose from RSS options.