Frequency Effects On The Depth And Breadth Of L2 Vocabulary Acquisition

"Frequency effect"means that the more times a certain thing occurs, the easier it is recognized. There have been heated arguments over the role of frequency in second language acquisition. Behaviorists regard frequency as an important factor in connecting stimulus and reaction, based on which the popular Audio-lingual Method at one time dominated foreign language teaching (Lado 1964). Connectionists believe that learners, through analysis of the repeated occurrences of language phenomenon, can form probabilistic patterns (WANG Chuming 2002). From the perspective of cognitive science and psychology, Nick Ellis (2002a) proposes that language learning is exemplar-based and it is a piecemeal learning of many thousands of constructions and the frequency-based abstraction of regularities within them. He views frequency as a dominant determinant of language acquisition. However, because of its importance and controversy, further study of this issue is worthwhile.Previous studies help to construct the frequency effects framework for second language vocabulary acquisition, which includes five major factors: input frequency, bar effect, lexical development, gap and output frequency, under the guidance of which, in Dec. 2006, an empirical study was conducted to investigate the word frequency level and word exposure acting on the depth and breadth of vocabulary acquisition for EFL learners. Evidence of 58 subjects'vocabulary learning is sought in comparing their vocabulary gains among different word frequency levels and different word exposures. Through interpretation of the quantitative and qualitative results, the following conclusions are generated: first, the frequency level of known words and the input frequency of unknown words affect quality of acquisition positively. Second, 6 exposures is supposed to be an ideal frequency for vocabulary development. Third, learners at different proficiency levels react differently to word exposures.In the research result is shown some pedagogical implications. First, increasing the input frequency of lexical items can facilitate vocabulary acquisition. Second, different ways of word input can help learners gradually deepen the understanding and widen the range of vocabulary knowledge. Finally, appropriate reading materials help language learners at lower proficiency take the first step to enlarge vocabulary so as to apply the frequency theory effectively to the second language vocabulary acquisition.