Task-based interaction and incidental vocabulary learning: a case study

This case study examines the vocabulary gains made by an adult learner of English as a second language as a result of performing four communication tasks. Gains were measured on comparisons of pre- and post-tests of vocabulary from the worksheets from the four tasks. These gains are discussed in relation to the interactional processes involving unfamiliar vocabulary. Explicit negotiation of word meaning appeared less deterministic of post-test improvements than use of words in the process of completing the task. While this result may to some extent be an artifact of test design, it is also true that when the group actively used vocabulary which was unfamiliar to the subject of this study, the embedding of this vocabulary in the context of the task and its interactive use are likely to have provided not only important information about word meaning but also the conditions whereby that meaning could be acquired. The placement of a word on task worksheets and the nature of a task, whether a split information task or a shared information task, both had a strong effect on use and acquisition of new vocabulary.