The Effects of Long-Term Vocabulary Instruction on Reading Comprehension: A Replication

A study that investigated the relationship between vocabulary instruction and reading comprehension was replicated and extended. The original study showed substantial gains in accuracy of word knowledge and speed of lexical access, but only marginal gains in comprehension. This latter result was attributable to methodological problems, and thus the comprehension measure was revised. In the present study, fourth graders were taught 104 words over a five-month period. Following instruction, these children and a group of uninstructed children matched on pre-instruction vocabulary and comprehension ability performed tasks to measure accuracy of word knowledge, speed of lexical access, and comprehension of stories containing taught words. Instructed children showed substantial advantage in all tasks. Reasons for these results, in contrast to studies that have failed to improve comprehension through vocabulary instruction, are discussed.