The GO model: a reconsideration of the role of structural units in guiding and organizing text on line.

Healy (1994) and Koriat and Greenberg (1994) offered different theoretical accounts of the missing-letter effect (MLE) in the letter-detection task, whereby a disproportionate number of letter-detection errors occur in frequent function words. Healy emphasized identification processes, whereas Koriat and Greenberg viewed the structural role of the embedding word to be crucial. Recent research suggests that neither position alone can account for the complete set of observations pertaining to the MLE. The present paper offers a theoretical integration of these competing explanations of letter detection in terms of a GO (guidance-organization) model of reading. This model specifies how structural processing of connected text helps guide eye movements to semantically informative parts of the text, enabling readers to achieve on-line fluency.