The effects of contextual diversity on incidental vocabulary learning

Abstract

This study investigated the effects of contextual diversity (CD) on second language incidental vocabulary learning. A total of 124 Japanese learners of English were allocated to a control group or 2 experimental groups, either a high contextual diversity (HCD) or a low contextual diversity (LCD) group. Participants in the HCD group encountered target words across three different texts that varied in genre and topic, while those in the LCD group read three different texts that shared the same genre and topic. Meaning recall and recognition tests were conducted at pretest, immediate posttest, and delayed posttest. Results showed that HCD outperformed LCD on meaning recognition at the delayed posttest. Moreover, learners with greater prior vocabulary knowledge tended to benefit more from contextually varied input, whereas such input may have adverse effects on learners with lower lexical proficiency. This study offers insights into the role of CD in incidental vocabulary acquisition and provides pedagogical implications for optimally incorporating input variability into L2 vocabulary instruction.