Effects of grammatical form-class set upon perception of grammatically ambiguous English words

Three independent groups of ten subjects each were assigned to three levels of set for grammatical form-class: noun set, verb set, and control. The effects of set upon perception of words ambiguous as to usage as noun or verb form were investigated, utilizing a factorial design. Main effects of set and form class were not statistically significant. Their interaction, however, reached significance at the 0.05 level. As predicted, tachistoscopic thresholds were lower for set-compatible words. Implications of these findings for perceptual integration vs. response bias explanations of the word frequency-threshold effect and for the psycholinguistic nature of grammatical form-class are discussed.