Reading Ability: Lexical Quality to Comprehension

Abstract The lexical quality hypothesis (LQH) claims that variation in the quality of word representations has consequences for reading skill, including comprehension. High lexical quality includes well-specified and partly redundant representations of form (orthography and phonology) and flexible representations of meaning, allowing for rapid and reliable meaning retrieval. Low-quality representations lead to specific word-related problems in comprehension. Six lines of research on adult readers demonstrate some of the implications of the LQH. First, large-scale correlational results show the general interdependence of comprehension and lexical skill while identifying disassociations that allow focus on comprehension-specific skill. Second, word-level semantic processing studies show comprehension skill differences in the time course of form-meaning confusions. Studies of rare vocabulary learning using event-related potentials (ERPs) show that, third, skilled comprehenders learn new words more effectively and show stronger ERP indicators for memory of the word learning event and, fourth, suggest skill differences in the stability of orthographic representations. Fifth, ERP markers show comprehension skill differences in meaning processing of ordinary words. Finally, in text reading, ERP results demonstrate momentary difficulties for low-skill comprehenders in integrating a word with the prior text. The studies provide evidence that word-level knowledge has consequences for word meaning processes in comprehension. Notes 1 CitationGernsbacher and Faust (1991; also CitationGernsbacher, 1990) explained less skilled readers' problems in meaning processing as due to problems in suppressing irrelevant meanings that are activated by a word. Differences between their mechanism-based account and the knowledge-based account of the LQH are discussed further in CitationPerfetti and Hart (2001). 2According to World Wide Words (CitationQuinion, July 2007), an August 2001 column in The Washington Post observed that “Too many Americans slouch toward a terminal funk of hebetude and sloth.” It was also the “word of the day” on Dictionary.com on January 24, 2004. 3The ERP results also produced evidence for early semantic effects at 200 msec that were more consistent across electrode sites and trial conditions for skilled comprehenders. They also showed 200-msec effects for the phonological task, comparing homophones versus nonhomophones that were comparable across the two groups.