Abstract: The cue-familiarity heuristic of FOK was examined in this study. The experiments were carried out on the basis of Metcalfe's study (Metcalfe, et al., 1993) which was considered as evidence in support of cue-familiarity hypothesis. The result of the experiment showed that, were 1×2 design (not 1×4 design in Metcalfe's study) adopted, a critical difference that couldn't be attributed to cue familiarity was observed. The result implied that,it is not only the cue familiarity or target accessibility but also the cue-target association that underlies the judgments of FOK.

Key words: FOK judgments, cue-familiarity heuristic of FOK