Individual Differences in Skilled Reading and the Word Frequency Effect

Variation in eye movement patterns can be considerable even within skilled readers. Here, individual differences and eye movements of 88 average-to-very-skilled readers were assessed to examine the reliability of previous observations of a reduced word frequency effect associated with skilled reading. Shorter fixation durations and higher skipping rates were observed for high frequency compared to low-frequency words. High scores on reading ability tests and vocabulary knowledge tests predicted reduced frequency effects in gaze duration in models with single individual differences predictors, demonstrated by faster reading of low-frequency words compared to low scorers. A principal components analysis grouped individual differences tests based on shared variance. High “lexical proficiency” predicted shorter gaze durations, reading times, and increased word skipping. “Lexical proficiency” and the Wechsler Individual Achievement Test–II comprehension test predicted a reduced frequency effect in go past times, and all tests apart from the Nelson Denny Reading Test comprehension test predicted a reduced frequency effect in sentence reading times. Data revealed surprising discrepancies in findings based on two subtests supposedly measuring comprehension (Nelson Denny Reading Test and Wechsler Individual Achievement Test–II), constituting an example of the jingle fallacy: the false assumption that two measures that share a name actually measure the same construct.