My colleagues and I found that deaf students using spoken language understood each other only 42 per cent of the time, and those using sign language understood each other 63 per cent of the time. I was quoted, incorrectly, as saying: "That is terrifying. It is not just a cognitive issue, but also one of basic language."
While our finding is surprising and disappointing, I would not call it "terrifying" because of the very diverse language backgrounds of most deaf students.
Although these findings and others I described at the "Language and Deaf Education" conference at Dunblane Hydro raise important concerns about educating deaf students, it is important to note that this particular study included only 64 students, not the 800 stated in your article, so the results must be considered to be tentative.
Further, the quotation got it backwards: the important thing is that such findings do not just reflect an issue of communication and language, rather they suggest that more basic cognitive issues are involved. That is, deaf students are not simply hearing students who cannot hear.
We have to understand how deaf students (and others with academic challenges) learn if we are to match instructional methods to their strengths and their needs. Only then can we fully support their educational attainments.
At present, it is unclear whether hearing teachers developing instruction and materials for hearing students in regular classrooms can achieve this: hence the change in my published statements about alternative educational placements for deaf students.
I believe the evidence is clear that "mainstream" educational settings may not be optimal for many deaf students, but there is no doubt that other students do succeed in those placements.
Professor, National Technical Institute for the Deaf (US) and University of Aberdeen