How large a vocabulary do Chinese computer science undergraduates need to read English-medium specialist textbooks?

This study specifically addresses the needs for English-medium textbook reading comprehension of Chinese computer science undergraduates who have already mastered about 3,300 general English word families prescribed by the Ministry of Education before entering university. Thirty textbooks on various subjects of computer science were chosen to build a Computer Science Textbook Corpus (CSTC) containing 7.51 million running words. Based on criteria of range, frequency, and dispersion, 356 word families outside the 3,300 items within students' knowledge were extracted to form the Computer Science Vocabulary List (CSVL). The CSVL accounted for 4.79% of the tokens in the CSTC but only 0.39% in a fiction corpus. The CSVL, combined with students' lexical repertoire acquired from secondary education, provided 95.16% coverage of the corpus, reaching the minimum requirement for reading comprehension suggested by Laufer (1989). By analyzing the overlapping proportion of related word lists pairwise, this study further established that the development of specialized word lists achieved the best efficiency if targeting at a homogenous audience. (C) 2020 Elsevier Ltd. All rights reserved.