There have been inconsistent findings in previous second language research on the effect of vocabulary glossing on reading comprehension (Davis, 1989; Jacobs, Dufon, & Fong, 1994; Johnson, 1982; Pak, 1986). The present study was undertaken to extend this body of research in two ways: (a) by including another set of second language learners, another text, and another set of vocabulary glosses, accompanied by rigorous experimental procedures; and, (b) by considering the possible interaction of other variables with glossing. These other variables were: psychological type, tolerance of ambiguity, proficiency, frequency of gloss use, perceived value of gloss use, and time on task.

Glossing can be situated in the context of recent work on the reading process (Eskey, 1988; Lesgold & Perfetti, 1981; Rumelhart, 1980; Stanovich, 1980) and learning strategies (Cohen, 1990; O'Malley & Chamot, 1990; Ojrford, 1990; Wenden, 1991). Glossing strengthens the bottom-up component of the reading process. The use of glossing is one of several possible repair strategies that readers can use when they recognize comprehension breakdowns.

One hundred sixteen U.S. college students enrolled in a third-semester Spanish course participated in the study. They were randomly assigned to one of two conditions, with half reading an unglossed Spanish text and half reading the same text accompanied by English glosses. After reading the text, participants were asked to write as much of the text as they could recall. Results showed a significant effect for glossing but no significant interactions between the treatment and any of the other variables. Suggestions are made as to the optimal use of vocabulary glosses.