ABSTRACT

Modern vocabulary size tests are generally based on the notion that the more frequent a word is in a language, the more likely a learner will know that word. However, this assumption has been seldom questioned in the literature concerning vocabulary size tests. Using the Vocabulary of American-English Size Test (VAST) based on the Corpus of Contemporary American English (COCA), 403 English language learners were tested on a 10% systematic random sample of the first 5,000 most frequent words from that corpus. Pearson correlation between Rasch item difficulty (the probability that test-takers will know a word) and frequency was only r = 0.50 (r² = 0.25). This moderate correlation indicates that the frequency of a word can only predict which words are known with only a limited degree of and that other factors are also affecting the order of acquisition of vocabulary. Additionally, using vocabulary levels/bands of 1,000 words as part of the structure of vocabulary size tests is shown to be questionable as well. These findings call into question the construct validity of modern vocabulary size tests. However, future confirmatory research is necessary to comprehensively determine the degree to which frequency of words and vocabulary size of learners are related.

摘要

现代词汇量测试通常基于以下概念：单词在语言中的频率越高，学习者越可能知道该单词。但是，这个假设在有关词汇量测试的文献中很少受到质疑。使用基于当代美国英语语料库（COCA）的美国英语规模测试词汇（VAST），对来自该语料库的前5,000个最常见单词的10％系统随机样本进行了403名英语学习者的测试。Rasch项目难度（应试者知道一个单词的概率）与频率之间的Pearson相关性仅为r = 0.50（r ² = 0.25）。这种适度的相关性表明一个单词的频率只能以有限的程度预测哪些单词是已知的，并且其他因素也影响词汇的获取顺序。另外，将词汇级别/ 1000个单词的带用作词汇量测试结构的一部分也被证明是有问题的。这些发现使人们质疑现代词汇量测验的构造效度。但是，未来的验证性研究对于全面确定单词的频率和学习者的词汇量之间的相关性是必要的。