The comprehensibility of reading texts in National Tests in English. A quantitative study of Swedish EFL learners’ vocabulary size and lexical coverage

Sammanfattning: Previous research has indicated a positive correlation between vocabulary size and reading comprehension (Grabe, 2009; Hu & Nation, 2000; Laufer, 1989; Laufer, 1992; Stæhr, 2008). Over the past decade, statistics have shown that Swedish upper secondary learners of English as a foreign language (henceforth EFL) are less proficient in reading comprehension as opposed to other language skills in the Nationals tests (NTs). Therefore, this study aims to examine the relationship between Swedish EFL learners’ receptive vocabulary size and lexical text coverage of the reading texts in the NTs. A total of 89 students from two upper-secondary courses (English 5 and 6) completed the revised Vocabulary Levels Test (Schmitt, Schmitt & Clapham, 2001). Two NTs from both courses were analyzed in a Lexical Frequency Profile program to determine the vocabulary size needed to reach 98% lexical coverage and consequently adequate reading comprehension (Hu & Nation, 2000; Nation, 2006). The results revealed that a majority of the students do not reach the 8,000–9,000 vocabulary size that is needed in order to achieve adequate reading comprehension of the whole texts. Furthermore, about 14–23% of the students display a vocabulary size below the 95% threshold level suggested by other researchers (Laufer & Ravenhorst-Kalovski, 2010), i.e. more than the 12% that statistically fail the reading comprehension part of the NTs. Suggestions for future research indicate the need to incorporate the learners’ reading comprehension scores to further validate the correlation between vocabulary size and the comprehensibility of reading texts in the NTs.