Developing the Appropriate Vocabulary Size For Extensive Reading in Korean EFL Contexts

This paper provides the appropriate size of vocabulary and a word list for Korean English learners to practice extensive reading in school contexts. This study suggests 4,000 words that include 3,000 words from the current middle and high school textbooks and 1,000 content words from elementary school subject matters and core cultural knowledge to make extensive reading successful in Korean school contexts. The study adds to the national word list 1,000 words of core content words from elementary subjects because despite their importance for comprehension they are often omitted from the national list which simply selects words based on the criterion of range and frequency. To examine the validity of 4,000 words for extensive reading for Korean students, the study consulted with several English educational professionals to testify the efficiency of the word list and drew positive results from them. Also, the study examined the text coverage of the word list for the reading materials exposed to Korean students - school English textbooks in Korea, American elementary textbooks, and graded reader series - and acquired positive results from them as well. The reading materials showed at least 95% text coverage, which many scholars agree for an appropriate vocabulary size for L2 learners.