The Validity of Word Family Use in Receptive and Productive Vocabulary Size Tests

Abstract

This study examined the appropriateness of using the word family as a means of measuring vocabulary size. It has been argued that the regular ways in which the inflections and derivatives of a base word are formed make them relatively simple for students to understand once the meaning of the base word is known. However, this argument has been challenged by researchers who suggest that students may face difficulty understanding derivatives, and that the degree of difficulty may vary for receptive and productive tests. In order to test the hypothesis that knowledge of a base word implies knowledge of its derivatives, and to search for differences due to test type, the study tested 124 South Korean university students both receptively and productively. The participants also completed a questionnaire that focused on their vocabulary learning practices. The results suggest caution in assuming that base word knowledge entails derivative knowledge, in general, and with respect to both receptive and productive tests. The study found that productive tests resulted in greater base word-derivative score variation than receptive tests, that derivatives were more affected by test type than base words and that teaching-learning practices may have affected the participants’ knowledge of derivatives.