The effects of dictionary use on second language vocabulary acquisition: A meta-analysis

Abstract

Abstract This study reports on the results of a meta-analysis which investigates the effects of dictionary use on second language (L2) vocabulary acquisition, as well as the magnitude of the moderating effect of a number of moderator variables on the effectiveness of dictionary use in improving L2 vocabulary knowledge. A total of 125 effect sizes were gleaned from 44 studies, which represented 87 independent samples and included 3,475 participants. A random-effects model of the meta-analysis shows that the overall effect of dictionary use on L2 vocabulary acquisition is g = 2.10 (p < .01) for within-group studies and g = 1.03 (p < .01) for between-group studies respectively, which are both large in the domain of second language research. Subsequent moderator variable analysis reveals how treatment-related variables (timepoint, dictionary form, dictionary type, target lexical unit, vocabulary knowledge type, learning condition, and research setting), methodological variables (type of experimental design, presence of pretest, and assessment type), as well as learner-related variables (age and proficiency) might contribute to the variation across studies. Implications of the findings are discussed.