An Evaluation of the Vocabulary Usedin Iranian Efl Secondary and High Schooltextbooks Based on the Bnc Firstthree1000 High Frequency Word Lists

This study compares the vocabulary used in iranian efl secondary and high school textbooks with the first three 1000 high frequency word lists (1000, 2000, 3000) from the british national corpus (bnc). the bnc first three word lists consist of 3000 word families which form the basis of 16454 word types. using bnc lists and nation’s range program, the findings of this study show that while most of the words used in these textbooks are among the words most frequent used, they just make up 10% of the total words in the bnc first three 1000 high frequency word lists. this indicates that there is a wide gap between the size of the vocabulary knowledge presented in these textbooks and an ideal vocabulary knowledge (3000 word families) necessary for minimal reading comprehension. the results of this study help course designers and materials developers to reconsider the vocabulary selection in the preparation of language teaching texts and materials. they also inform teachers of the shortcomings in the textbooks and help them to try to find ways to bridge the gap.