This study examined the reading passages of the National Assessment of Educational Achievement (NAEA) and middle school English textbooks in terms of their readability and lexical difficulty. The readability was measured by using Flesch-Kincaid Grade Level Index, while their lexical difficulty was measured in terms of STTR (standardized type-token ratio), frequency of tokens per type, and vocabulary frequency levels by using VocabProfile and Oxford WordSmith Tools 7.0. The results showed that there was a gap between the readability of the English textbooks and that of the NAEA conducted from 2012 to 2014, while the readability between the English textbooks and that of the 2015 NAEA reached a comparable level. However, the textbooks from one publisher showed substantively lower readability than those from the other publishers and the NAEA. Secondly, regarding vocabulary frequency levels, the words in 1K and 2K accounted for more than 90% of the textbooks and the NAEA, while the NAEA had a higher STTR and lower frequency of tokens per type than the textbooks. It suggests that the NAEA employed more various words with less repetition than the textbooks. Pedagogical implications are discussed.

This study examines the difficulty of reading text in elementary school English textbooks. Four elementary school English textbook series published by three publishers were evaluated by Word Critical Factor (WCF). WCF considers cognitive demands for word recognition; it assesses the match of linguistic content in the text with the phonetically regular and high-frequency words that are associated with particular stages of reading development. For the analysis, all of the words that appeared in the reading and writing sections from four elementary school English textbooks were analyzed by two criteria, that is, the ratio of high frequency words and phonetically regular words among 100 running words, and the number of unique words in each textbook. The results showed that all four textbooks’ difficulty levels were very high considering the learner’s reading ability. This was due to the textbooks having a low repetition of words and also the complicated vowel patterns that were above the reading abilities of students. All of these factors combined are what have caused the difficulties presented in English textbooks. In conclusion, although the reading text introduces a variety of genres and activities for the development of reading skills, most reading text could not assist the reader’s cognitive processing.