Effectiveness of Explicit, Rich Vocabulary Instruction on Reading Comprehension and Word Knowledge of High School Students

Abstract

This study investigated the effects of explicit, rich vocabulary instruction on the word acquisition and reading comprehension of high school students. The quasi-experimental study employed a two-group pretest-posttest design, using students from two intact sophomore English classes. The treatment group received daily, explicit, rich vocabulary instruction, using semantically grouped words, for a period of eight weeks. The comparison group received traditional vocabulary instruction, using the same word lists as the treatment group; additionally, the comparison group received daily reading strategy instruction for the eight weeks. A fifty-item, multiple choice vocabulary assessment was administered as a pretest and posttest to both groups. Reading comprehension levels for treatment and comparison groups were measured through the use of the Star Reading (STAR) assessment (Renaissance Learning, 2011) as the pretest and the Alabama-mandated Quality Core End-of-Course Test for English 10 (ACT, 2011) as the posttest. While the treatment group’s vocabulary pretest-to-posttest scores showed a statistically significant increase, the anticipated accompanying increase in reading comprehension scores was not evident. The comparison group posttests also showed a statistically significant increase in vocabulary, and a lack of statistically significant improvement in reading comprehension results. Although previous research indicated the need for rich vocabulary instruction to improve reading comprehension, the results of this study indicate that a better method may be a combination of rich vocabulary instruction and reading comprehension strategies. In either case, findings from this study and others show that rich vocabulary instruction should be an integral part of the high school Language Arts curriculum.