Measuring productive derivative knowledge of vietnamese EFL learners: The role of headword scoring, vocabulary breadth, and headword familiarity

Abstract

A growing body of research has attempted to measure learners' productive derivative knowledge over the past few years. However, it remains unclear whether the exclusion of headwords in the scoring method would have any impact on derivative production. Moreover, the role of learners' vocabulary breadth has yet to be investigated with their headword familiarity. The present study thus filled in these gaps by exploring the extent to which Vietnamese EFL learners (N = 73) produced the derivatives of 90 headwords in a decontextualized form-recall test. The participants' scores were later examined in light of their vocabulary receptive knowledge (i.e., scores on the updated vocabulary levels test) and headword familiarity (i.e., knowledge of the form-meaning connections of headwords) using linear mixed-effects models. The results revealed that the learners could produce on average about one-fourth of the target derivatives, and those who mastered higher vocabulary levels produced more derived forms. However, their derivative-test performance in all examined word-frequency levels (1000–5000) differed significantly when headwords were scored and not scored. Furthermore, headword familiarity was a strong predictor of learners' production of derivatives, especially for those at higher vocabulary levels. Implications for researching derivatives and expanding L2 learners’ productive derivative knowledge are discussed.