Functional forms of frequency and contextual diversity effects in lexical decision

Abstract

Several recent papers have examined the functional form of frequency effects on lexical decision latencies in the context of specific mechanisms for the task. We (Adelman, Brown, & Quesada, in press) have recently provided evidence that contextual diversity (i.e., the number of contexts in which a word occurs), not word frequency, determines such latencies, and it is therefore of theoretical interest to examine the functional form of the relationship between these measures and lexical decision latencies. Here we outline the functional forms predicted by various lexical decision mechanisms and report statistics describing the fit of several functional forms—namely, rank, logarithmic, exponential, logistic, power, race, and APEX