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

TLDR

Previous work found large gains in word knowledge and lexical access but only modest comprehension improvements, attributed to methodological issues that prompted a revised comprehension measure. The study replicated and extended prior research on the relationship between vocabulary instruction and reading comprehension. Fourth‑grade students received instruction on 104 words over five months, after which both instructed and matched uninstructed peers completed tasks assessing word knowledge accuracy, lexical access speed, and comprehension of stories containing the taught words. Instructed children outperformed uninstructed peers on all measures, and the authors discuss why these results differ from prior studies that failed to improve comprehension through vocabulary instruction.

Abstract

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.