The Effects of Vocabulary Instruction: A Model-Based Meta-Analysis

Abstract

This paper reports a meta-analysis of studies concerned with the effects of vocabulary instruction on the learning of word meanings and on comprehension. This analysis was used to examine two questions: Does vocabulary instruction have a significant effect on children’s comprehension of text? What types of vocabulary instruction are most effective? In response to the first question, a mean effect size of .97 could be attributed to vocabulary instruction for comprehension of passages containing taught words and of .30 for global measures of comprehension, both of which are significantly different from zero. For the second question, it was suggested that the most effective vocabulary teaching methods included both definitional and contextual information in their programs, involved the students in deeper processing, and gave the students more than one or two exposures to the to-be-learned words. In addition, the mnemonic keyword method was found to have reliable effects on recall of definitions and sentence comprehension.