The Effects Of Keyword Caption Ratios On Chinese Junior High School Students’ Incidental Vocabulary Acquisition

With the widespread application of multimedia technology in foreign language teaching,more and more English video materials are used in English teaching.As an important mode of language input,video captions have received increasing attention from researchers in foreign language teaching.Many studies have confirmed that video captions have a positive effect on second language learners’ incidental vocabulary acquisition,listening and video comprehension.And a number of studies have begun to focus on the impact of keyword captions on second or foreign language learning.However,to the best of the author’s knowledge,few studies have investigated the effects of different ratios of keyword captions on foreign language learning.Therefore,this study aims to explore the effects of different ratios of keyword captions on junior high school students’ incidental vocabulary acquisition through empirical research.Based on the Input Hypothesis,Noticing Hypothesis and Cognitive Theory of Multimedia Learning,this research endeavors to investigate the effects of keyword caption ratios on junior high school students’ incidental vocabulary acquisition,trying to answer the following two research questions:(1)Do different ratios of keyword captions have a significant effect on junior high school students’ incidental vocabulary acquisition? And what is the difference?(2)What keyword caption ratio has the best effect on junior high school students’ incidental vocabulary acquisition,judging from the form recognition and meaning recall of the target words?Five parallel classes of Grade Eight in Qingzhuhu-Xiangyi Foreign Language School of Changsha were chosen for this study.Based on the five groups’ scores on the vocabulary level test,the author chose 35 students from each class as subjects for this study and ensured that the five groups had a similar vocabulary size.Additionally,all the participants were required to complete a vocabulary pretest to ensure that all the target words in the immediate post-test were not acquired by them before the formal experiment.Four groups constituted experimental groups and watched the same English video with 10%,30%,50% keyword captions and full captions respectively.Meanwhile,one group was selected as the control group to watch the video without captions.Subsequently,participants in these five groups completed an immediate vocabulary post-test after watching a five-minute English video.The effects of participants’ incidental vocabulary acquisition were measured by the immediate vocabulary post-test.And in this study,the immediate post-test included two aspects which were form recognition and meaning recall of the target words.Finally,the experimental data were analyzed,revealing the following results:(1)Different ratios of keyword captions had a significant effect on junior high school students’ incidental vocabulary acquisition.The 50% keyword captions group performed best in the immediate vocabulary post-test,followed by the full captions group,30% keyword captions group,10% keyword captions group,and the no-caption group did worst.Additionally,there were significant differences between the 50% keyword captions group and the other four groups,and the 50% keyword captions group scored significantly higher than the other four groups in the immediate vocabulary post-test.However,the results of the immediate vocabulary post-test revealed that there were no significant differences between the 10% keyword captions group and the 30% keyword captions group or the 30% keyword captions group and the full captions group.(2)The 50% keyword captions group got the highest mean score in word form recognition and meaning recall tests.However,there were no significant differences among the three keyword captioning groups(10%,30% and 50% keyword captioning groups)in the form recognition test.And in the meaning recall test,there was no significant difference between the 50% keyword captions group and the full captions group.In summary,among the five groups,the 50% keyword captions group is the most effective one for acquiring vocabulary incidentally.The findings of this study have important pedagogical implications for English teachers.Firstly,foreign language teachers should pay attention to captions,especially the positive effect of the appropriate ratio of keyword captions on students’ incidental vocabulary acquisition.Secondly,teachers should enhance their information technology capacity and process video captions through some video editing software to help students acquire vocabulary from English videos better.For example,to improve the salience of the keywords or target words in the video.Finally,when choosing captioned English videos as language teaching materials,teachers should take into account the new word rate of the selected video,and the new word rate should not exceed 5%,which can better promote students’ incidental vocabulary acquisition.