Vocabulary knowledge as predictor of EFL university students’ writing performance

This study aims to examine the role of vocabulary knowledge in predicting EFL college students’writing performance. The study particularly focused on the two forms of lexical knowledge(receptive and productive) in a way to compare their contribution to the students’ writing ability. Forty-two college students participated in series of tests: grammar knowledge test and the twoversions of vocabulary knowledge test (receptive knowledge test and productive knowledge test intwo forms, i.e., definition writing and sentence writing). These students also wrote an argumentativeessay on a given topic and responded to a survey questionnaire. The students’ writing performancescores were regressed on 4 independent variables (grammar knowledge, receptive vocabularyknowledge, and two forms of productive vocabulary knowledge (definition writing and sentencewriting abilities) to identify a potential predictor of their writing performance. The results show thatproductive vocabulary knowledge in both tasks (sentence and definition writing) was the significantpredictor of writing performance score (ß = .454, ß = .436, respectively). On the other hand,receptive word knowledge was not found to be a significant predictor. Writing performancerevealed the strongest correlation with the two forms of productive vocabulary knowledge, but notwith receptive knowledge. These findings are discussed.