This study aimed to investigate the relationship between lexical coverage and TV viewing comprehension. Previous studies have indicated that 95% to 98% of lexical coverage may be needed for reading comprehension (Hu & Nation, 2000). To understand informal listening passages, lower coverage figures (95%-90%) may suffice. However, no study has researched the lexical coverage needed to understand audiovisual texts. We adopted a counter-balanced within-participants design, in which 5%, 10%, or 20% of the words in four 2-min documentaries were replaced with nonwords. Native and non-native speakers of English participated in this study. Results showed that comprehension scores decreased as lexical coverage decreased; comprehension at 100% coverage was significantly higher than 90% and 80% in the two groups; and optimal adequate comprehension is achieved with an optimal lexical coverage of 95%, whereas minimal adequate comprehension is reached with a minimal lexical coverage of 80%.

中文翻译：

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L1 和 L2 观看理解中的词汇覆盖率


本研究旨在调查词汇覆盖率与电视观看理解之间的关系。以前的研究表明，阅读理解可能需要 95% 到 98% 的词汇覆盖率（胡 & Nation，2000 年）。要理解非正式的听证会段落，较低的覆盖率数字 （95%-90%） 可能就足够了。然而，没有研究研究理解视听文本所需的词汇覆盖率。我们采用了一种平衡的参与者内部设计，其中四部 2 分钟的纪录片中 5%、10% 或 20% 的单词被替换为非单词。英语母语和非母语人士参与了这项研究。结果显示，理解分数随着词汇覆盖率的减少而下降;两组 100% 覆盖率的理解率显著高于 90% 和 80%;最佳词汇覆盖率为 95% 时可实现最佳充分理解，而最小词汇覆盖率为 80% 时达到最低充分理解。