The effects of lexical densities and task types on Chinese students’ incidental vocabulary acquisition

This study examines the effects arose by different lexical densities (2%, 5%) and task types (mind map, continuation task) on Chinese senior high students. Four classes of intermediate-level Chinese EFL learners were randomly assigned to four groups, where the treatment condition for each group includes two variables (group1: 2%+mind map, group2: 5%+mind map, group3: 5%+continuation task, group4: 2%+continuation task). It was found that (1) lexical density (2%, 5%) would not result in a significant difference on incidental vocabulary acquisition; (2) Both tasks would lead to a significant difference on incidental vocabulary acquisition and (3) mind map showed superiority in enhancing receptive vocabulary, productive vocabulary and word retention under the text of 5% of lexical density; (4) 2% of lexical density more facilitated output vocabulary when the continuation task was administered. Pedagogical implications of these results for EFL vocabulary acquisition are discussed.