Contextual diversity, not word frequency, determines word naming and lexical decision times

Word frequency is the most important known predictor of word naming and lexical decision times. It is, however, confounded with contextual diversity, the number of contexts in which a word has been seen. With a normative, corpus-based measure of contextual diversity, word frequency effects were eliminated by contextual diversity (but not vice versa) across three naming and three lexical decision data sets, using any of three corpora to derive the frequency and contextual diversity values. This result is incompatible with existing models of visual word recognition, which attribute frequency effects directly to frequency, and is particularly problematic for accounts in which frequency effects reflect learning. It is argued that the result reflects the importance of likely need in memory and that the continuity with memory suggests using principles from memory research to inform theorizing about reading