二语字幕影视生词密度及词汇宽度要求分析

摘要

With the introduction of unknown word density into captioned-video-based language teach-ing,this paper first establishes the unknown word density threshold to achieve adequate understanding of second language captioned videos,i.e.5% and 2%,based on the previous relevant studies on w ritten and spoken discourses,and then analyzes the corresponding vocabulary width requirements through experi-ments so as to provide an vocabulary width aim for captioned-video-based teaching.The results show:in general,knowledge of the most frequent 4000 word families plus proper nouns and marginal words provide 5% unknown word density,and the most frequent 7000 word families plus proper nouns and marginal words provide 2% density;there is no significant difference between American and British captioned videos at 5% density,but the vocabulary width requirement of American captioned videos is a bit lower than that of British at 2% density;the vocabulary width requirements of different types range from 4000 to 5000 families plus proper nouns and marginal words at 5% coverage,and from 6000 to 10000 families at 2%coverage.%本文首次将生词密度这一概念引入字幕影视的教学研究,首先基于先前研究确定的对书面和口语语篇实现足够理解所需的生词密度阈值,将5% 和2% 确定为对二语字幕影视实现足够理解所需生词密度的阈值,进而通过实证分析相应的词汇宽度要求,从而为字幕影视教学提供一个有效的词汇宽度教学目标.结果表明:总体而言,掌握最常用的4000词族加上专有名词和边缘词可使字幕影视生词密度达到5%,掌握最常用的7000词族加上专有名词和边缘词才能达到2% 的生词密度;英美字幕影视间在5% 生词密度时不存在显著差异,而在2% 层次,美国影视的词汇宽度要求略低于英国影视;不同类型影视达到5% 生词密度所需词汇宽度为4000到5000词族加上专有名词和边缘词,而达到2% 生词密度则为6000到10000词族加上专有名词和边缘词.