Abstract
Vocabulary competence has been identified as one of the indicators for the level of L2 literacy (Hinkel, 2006; Schmitt, 2000). Previous studies point out that the command of a rich L2 word repertoire can contribute to the quality of learners’ reading comprehension and writing performance positively (Astika, 1993; Laufer & Nation, 1995). To promote the L2 learners’ literacy, embedding vocabulary learning into reading tasks is one of the most common teaching practices. However, it is evident that learning vocabulary incidentally from reading texts is insufficient to expand the learners’ productive vocabulary (Huang, H.T., 2004; Lee & Munice, 2006). To enhance the learners’ sophisticated mastery of productive vocabulary, explicit lexical instruction should be emphasized. In tertiary education, the Academic Vocabulary List (Coxhead, 2000, AWL) is a crucial learning goal, as it contains the high-frequency words applicable to a wide range of academic disciplines. Offering the explicit academic word instruction and providing opportunities for word production may instrumentally facilitate the transfer of the learners’ receptive vocabulary into active use (Coady, 1997; Coxhead, 2006). Also, vocabulary learning is claimed to be assisted by recent innovative referencing tools such as a concordance (Horst, et al., 2005; Kaur & Hegelheimer, 2005). Nevertheless, few studies explore whether and how explicit academic vocabulary instruction with the online concordancers can enhance the learners’ productive vocabulary for writing.The present study aims to investigate the effects of self-designed online academic vocabulary instruction on college learners’ writing performance. Adopting the AWL as the basis, the online instruction was developed on a web platform, MOODLE (a freeware for online course construction) with the integration of a useful concordancer. Twenty-five EFL college students of English majors participated in the project. Three features of the online course were designed: (a) the explicit academic vocabulary lessons (wordlists, weekly lecture notes), (b) online quizzes (gap-filling, crosswords), and (c) learners’ vocabulary logs uploading section. Within the eight-week lexical teaching, the regular instructional flow included a reading task highlighting academic words, explicit academic word instruction, the learners’ hands-on concordancing (http://candle.fl.nthu.edu.tw/collocation), and a pair-writing task.To gauge the developments of the learners’ academic vocabulary after the eight-week instruction, various measures were used at three time points: two types of vocabulary tests, three timed-essay tests, and two questionnaires. At the beginning, a background questionnaire probed into the learners’ prior lexical learning experiences. To estimate the instructional gains on the size and depth of learners’ vocabulary, the VLT (Schmitt et al., 2001) and the VKS (Joe, 1998) were adopted in pre- and post-tests. The writing samples from the three essay tests (at the pretest, posttest, and four-week-after delayed posttest stages) were analyzed to reveal the learners’ “free active” academic vocabulary use (Laufer, 1998). The VocabProfiler program (Cobb, 2004, http://132.208.224.131/) was used to show the Lexical Frequency Profile (Nation & Laufer, 1995) ratios of 1000-words, words in AWL and offlist words in the learners’ writing. The overall writing quality was further rated by two TEFL graduate students via the ESL Composition Profile (Jacob et al., 1981) from a comprehensive perspective. Finally, the learners’ attitudes towards the design and effectiveness of online instruction were elicited via an evaluation questionnaire.The t-test comparison showed that the EFL college learners did not expand the size of their academic vocabulary significantly, but enhanced the depth. Second, given the ANOVA analyses on the LFP ratio, the learners incorporated more academic words correctly in their post-instructional essays. Their overall writing quality was also upgraded, with the substantial improvements on lexis and grammar. Moreover, their lexical richness in writing partially sustained over the span of four weeks. Their lexical ability appeared to be positively correlated to their writing scores, particularly for their post-instructional performances, according to the Canonical Analysis. Third, the learners generally perceived the overall lexical instruction as effective for the expansion of their productive academic vocabulary. The afore-mentioned results show that the explicit academic vocabulary instruction can relatively enlarge the learners’ productive vocabulary for writing. The efficacy of the explicit lexical instruction is partially supported, as it combines the benefits of incidental and intentional lexical learning. Pedagogically, the present study appears to display a feasible lexical syllabus of how to explicitly address the academic words for the college learners. With the advance of the learners’ academic words use in writing, the L2 learners can socialize into the academic community with greater ease (Corson, 1997; Coxhead, 2006).