An Empirical Study On The Effects Of Output Tasks On L2 Vocabulary Acquisition

This dissertation reports an empirical study on the effects of input and output activities on second language acquisition of word meanings and collocations by Chinese learners of English. It tends to explore how Swain's Output Hypothesis is related to vocabulary learning, and how teaching tasks can be effectively designed and implemented.The study was implemented in a college in Guangzhou. Subjects were 60 English majors coming from two first year classes serving as the experimental group and the control group respectively. The whole treatment consisted of three phases. An immediate posttest was conducted right after phase 3 of the treatment; a delayed posttest was imposed one week later. Between-group and within-group comparisons were made to see whether the experimental group outperformed the control group in gains of receptive and productive knowledge of word meanings and collocations and whether the two groups could retain their gains.There were two major findings. First, the experimental group did better than the control group in both posttests no matter in terms of productive or receptive gains in word meanings. Second, the experimental group also outperformed the control group in productive gains of collocations, but not in receptive gains of collocations. Therefore, we conclude that such findings provide empirical support Swain's (1985, 1995) claim that output promotes noticing and learning language forms. The fact that the experimental group did not do significant better than the control group in the gains of receptive knowledge of collocations may be due to the inherent nature of collocations.An addition finding in the present study was that both groups' productive knowledge of word meanings lost more quickly than receptive knowledge, indicating that output tasks need to be done frequently so as to help retain productive knowledge better. Besides, the situation with the collocations was a bit different. Both groups retained the productive and receptive knowledge very well, suggesting that the learning of collocations follows a different pattern from the word meanings. Though productive knowledge of word meanings fell quickly, both productive and receptive knowledge of collocations stuck to the learner's mind firmly. This may suggest that we really need to spend time and energy on collocations as the efforts are really worthwhile.Finally, some pedagogical implications for EFL classes in China were put forward.