Effects Of Word Exposure Frequency On EFL Learners' Incidental Vocabulary Acquisition

This empirical study is designed to investigate the effects of word exposure frequency on EFL learners'incidental vocabulary acquisition and to determine the number of encounters needed to learn a word; the effects of contextual richness and part of speech are also examined to see whether they have a role in vocabulary learning. Evidence for subjects'vocabulary learning is sought in comparing their vocabulary gains among different word occurrences, different categories of part of speech and different contextual richness. The statistical techniques employed for analysis are descriptive statistics, Repeated-measure ANOVA and Bivariate Correlations. Through the interpretation of the quantitative and qualitative results, we can generate the following conclusions:1) The subjects have acquired both productive vocabulary knowledge and receptive vocabulary knowledge after reading a text in the present study.2) Word exposure frequency influenced vocabulary gains. In the test of productive vocabulary knowledge, a word should at least be exposed 8 times in a text for it to be better learned by learners than those word exposed once or twice. In the test of receptive vocabulary knowledge, a word should at least be exposed 9 times in a text for it to be better learned by learners than those word exposed once.3) Part of speech influences vocabulary gains. Both in the supply-definition test and the select-definition test, the mean score of Adjective is higher than that of Verb in the tests of three times. We conclude that Adjective is the easiest to acquire by learners, Verb the most difficult.4) Part of speech does not influence vocabulary gains when the words have the same exposure frequency in the text.5) Contextual richness does not influence students'vocabulary acquisition. Based on the above conclusions, some pedagogical implications are made in the following:Firstly, since words can be acquired from reading, teachers should guidance and encourage students to do extensive reading in their leisure time, which is an effective approach to expand students'vocabulary. However, the difficulty of texts and the number of novel words should be considered in the selection of reading materials.Secondly, the results and conclusions may provide some implications to the compiling of extensive reading materials. As the results from the present study show that word exposure frequency has a substantial impact on vocabulary learning, thus, the compilers can mediate the exposure frequency of novel words in a text in order to make...