Materials Coherence in General and ESP Textbooks in PNU: A Vocabulary Level Analysis

Abstract

The present study is the analysis of General English, semi-ESP and ESP textbooks taught at Payame Noor University (PNU) for Psychology major. The purpose is to determine whether the lexical content of the semi-ESP book is appropriate in terms of the frequency range of the words to be used as the link between General English and ESP courses. The expected pattern of word frequency is that a high percentage of low frequency words will be indicated in the ESP textbook whereas high frequency words will be found mostly in General English; a high percentage of AWL words must also be observed in the semi-ESP textbook. To check the actual pattern in the textbooks against the expectations, the Lexical Frequency Profiles (LFPs) of all the reading texts of the textbooks were obtained by means of VocabProfile program. The analysis of Chi-square test revealed that in all three books, the largest percentage of words are from the first and second 1000 frequency ranges, while the expectation of a larger percentage of AWL words in Semi-ESP book was not met. In other frequency ranges, also, there were not any significant differences between the percentages of the words.