Working memory and prior vocabulary knowledge in incidental vocabulary learning from listening, reading, reading-while-listening, and viewing captioned videos

This study explores how certain input modes (i.e., listening, reading, reading while listening, and viewing captioned videos) affect incidental vocabulary learning in a foreign language context. It also examines the roles of learners' prior vocabulary knowledge and working memory in incidental vocabulary learning using the examined input modes. A total of 150 EFL students at a Chinese university were randomly and equally assigned to the four input modes, as well as a control group only took tests. Forty-eight words were chosen as target words. Participants either listened, read, read while listening to, or watched transcripts during viewing a documentary video. Incidental vocabulary learning outcomes were assessed through a two-part vocabulary test (i.e., form and meaning recognition). Mixed effects model results showed that incidental learning and retention of form and meaning recognition were superior under the caption-viewing condition followed by the reading-while-listening, reading, and listening conditions. Findings also revealed that prior vocabulary knowledge and working memory play distinct roles in incidental learning and retention of form and meaning recognition for each input mode. Relevant implications for vocabulary instruction are provided.