Are French Fries a Vegetable? Lexical Typicality Judgement Differences in Deaf and Hearing Learners

Deaf and hard-of-hearing (DHH) learners are known to have vocabulary knowledge and language outcomes more heterogeneous than their hearing peers, with a greater incidence of difficulties presumably related (both as cause and effect) to documented challenges in academic domains. In particular, there is increasing evidence that differences may exist in the ways that semantic networks are structured and accessed in DHH and hearing learners. Individuals' judgments of word typicality offers a window into their semantic networks, revealing internal relationships in the mental lexicon. In the present study, 90 DHH and hearing college-aged learners provided typicality ratings at two points in time for 120 words common words considered to be central, borderline, or non-members of six categories. DHH and hearing participants differed in terms of their word knowledge, rating consistency, and rating magnitudes. Relative to hearing peers, DHH participants reported not knowing more of the words, but rated all words as being more typical than did hearing participants and rated the typicality of items more consistently over time. Implications of these findings for understanding mental lexicon structure for DHH and hearing learners, interpreting previous research, and constructing stimuli for future research are discussed.