Vocabulary size and type goals in advanced EFL and ESL classrooms. A review of research on lexical threshold, lexical coverage, reading and listening comprehension

Abstract: This paper examines how research on lexical threshold and lexical coverage relates to L2 proficiency in reading and listening comprehension, and how this in turn will impact what types of vocabulary should be taught in advanced ESL and EFL classrooms. The research reviewed contains estimations of how much English vocabulary L2 users need in order to do certain things in English, such as reading a novel, watching a movie or understanding everyday conversations. The results indicate that to reach lexical coverage of 98 percent, which is necessary to gain an adequate reading comprehension, a vocabulary size of 8,000-9,000 word families is needed, whereas around 5,000 word families may suffice if the expected level of comprehension is lowered to 95 percent lexical coverage. However, the lexical threshold is ultimately dependent on the expected level of comprehension. The vocabulary size needed to understand spoken English is considerably lower than that needed to understand written English. In order to attain the needed amount of vocabulary, it seems that the traditional vocabulary type teaching, focusing on high-frequency words and the Academic Word List, is no longer sufficient. Rather, more pedagogical focus should be placed on mid-frequency vocabulary, which has previously been overlooked.