Exploring EFL learners' lexical competence: What numbers tell us about words

An important finding of research on the lexical aspect of second language acquisition is that lexical competence is multidimensional. It encompasses several aspects of knowledge and can be described in terms of separate (listing and describing all aspects and dimensions of lexical knowledge) or global traits models (describing only a few critical dimensions). Starting from Housen Bulté Pierrard and Van Daele’s (2008) theoretical conceptualisation of lexical proficiency, i.e. its declarative component, and Read’s (2000) definition of lexical richness, this study explores how well various lexical measures portray EFL learners’ productive lexical proficiency. The declarative component of lexical competence includes the constructs of size, width and depth of lexical knowledge, which are inferred from the following lower-order constructs: lexical diversity (the number of different words used), lexical density or productivity (the percentage of content words), lexical sophistication (the proportion of low-frequency words) and lexical errors. To answer the research questions, 100 essays written by B2 EFL learners are analysed. The paper presents and discusses the results of statistical analyses used to explore the relationship between ‘the numbers’ (i.e. various linguistic measures) and a more impressionistic, holistic evaluation of lexical competence conducted by trained raters.