This study described and analyzed the vocabulary of 4 current, best-selling core reading programs and developed word lists based on these analyses. Results showed a good deal of similarity but also some significant differences among the programs. Across grades 1–6, all of them included a substantial number of tokens (approximately 380,000–660,000) and a substantial number of types (approximately 18,000–21,000). Approximately 90% of words were quite frequent, among the 4,000 most frequent English words. Most words were not repeated frequently; about 45% occurred only once or twice. Approximately 3,500 words were identified as relatively frequent and widely dispersed and about 1,000 words as relatively frequent, widely dispersed, and likely to be unknown. The lists developed include types in the programs, word families in the programs, frequent word families, general-utility word families, and challenging general-utility words families. The discussion centers on educational uses of the findings and the lists.

中文翻译：

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核心阅读课程的词汇

本研究描述和分析了 4 个当前最畅销的核心阅读程序的词汇，并在这些分析的基础上开发了词汇表。结果显示出很多相似之处，但程序之间也存在一些显着差异。在 1-6 年级中，所有这些都包括大量标记（约 380,000-660,000）和大量类型（约 18,000-21,000）。在 4,000 个最常用的英语单词中，大约 90% 的单词相当频繁。大多数单词不经常重复；大约 45% 只发生一次或两次。大约 3,500 个单词被确定为相对频繁和广泛分散，大约 1,000 个单词被确定为相对频繁、广泛分散和可能未知。开发的列表包括程序中的类型、程序中的词族、常用词族、通用词族和具有挑战性的通用词族。讨论集中在研究结果和列表的教育用途上。