Abstract
In terms of incidental vocabulary learning, reading is commonly regarded as the major source of vocabulary acquisition for both L1 and L2 learners. Extensive reading then is encouraged as a means of enhancing vocabulary knowledge. Apart from the advantage of vocabulary acquisition, as long as the reading is comprehensible, the learners will also acquire knowledge of grammar and improvement of the four skills, listening, speaking, reading and writing (Krashen, 1989; Cho & Krashen, 1994). Hence, it is suggested that through reading, learners can gain both receptive and productive vocabulary knowledge. Nevertheless, some researchers have argued that reading cannot be the only source of language acquisition; output, such as speaking and writing, should also play some role in the language learning process (Swain, 1985; Swain & Lapkin, 1995). Some studies have found an asymmetric processing of receptive and productive vocabulary knowledge, based on the types of tasks done by learners. Most of these studies investigated the results of vocabulary gains in view of the learning order of the language, either from L1 to L2 order or from L2 to L1 order. These kinds of tasks did not represent incidental vocabulary acquisition since the main goal of the tasks was vocabulary learning. In addition, most of the instruments used in the studies were translation only. Owing to the inconsistencies in the empirical results and the lack of measurement of productive vocabulary knowledge, this study, therefore, was conducted to explore the effects of input and output tasks on incidental vocabulary acquisition. There were two groups in this study, one doing only the input task and the other emphasizing output. The input task included reading, word-definition matching, translation, and reading comprehension questions. These exercises did not require learners to produce the English words at all. For the output group, the exercises were reading and compositions. After reading an article, learners needed to write compositions using all the target words. There were 50 target words and the treatments lasted 8 weeks. Sixty-seven EFL first year senior high school students from two classes were recruited to participate in the study. In order to randomly assign the tasks, half the students in each class were in the input task group and the other half in the output task group. A pretest, five immediate and delayed posttests, and final receptive and productive posttests were used as the instruments in this study. Receptive vocabulary knowledge was measured by an adaptation of the Vocabulary Knowledge Scale (Paribakht & Wesche, 1996) and English-Chinese translation. The measures for productive knowledge were sentence writing and Chinese-English translation. The writing tests were scored by two raters, one a Chinese English teacher and the other a native English speaker. Data analysis yielded the following results. First, there was no significant difference in scores between the input and output task groups on immediate or delayed posttests. Hence, this study suggests that the retention of receptive and productive vocabulary is not greatly affected by the types of tasks used and that both input and output tasks help learners acquire not only receptive vocabulary knowledge but also productive knowledge. Therefore, teaching implications are that teachers should provide more reading tasks because reading can benefit not only vocabulary acquisition but also the development of literacy. Sentence writing did provide learners opportunities to use the words in a productive way, but it did not lead them to the awareness of the proper use of the words. Regarding directions for future research, more subjects and target words should be included in the experiment and the rating scale for productive vocabulary tests should be refined.