Electronic Thesis and Dissertation Repository


Doctor of Philosophy




Faez, Farahnaz

2nd Supervisor

Webb, Stuart

Joint Supervisor


Productive depth of vocabulary knowledge (PDVK) is associated with writing and speaking skills (Laufer & Goldstein, 2004). These skills are essential for English for Academic Purposes (EAP) students, who have difficulties with expressing themselves in oral presentations or written assignments (Evans & Green, 2007). As a result, diagnostic measurement of PDVK is of vital importance, especially in regard to the most frequent 1,000 word families because these word families cover 81% of written text and 85% of spoken text (Nation, 2006).

Depth of vocabulary knowledge has been investigated and measured in various studies (see Chen & Truscatt, 2010; Pigada & Schmitt, 2006; Schmitt & Meara, 1997; Schmitt, 1998, 1999; Webb, 2005, 2007a, 2007b, 2007c, 2009a, 2009b) leading to successful multi-dimensional batteries of tests for its measurement. However, no study, to date, has productively measured the depth (and strength) of knowledge of the most frequent words. Nation’s (2013) conception of vocabulary knowledge—the proposition that vocabulary knowledge has three main aspects of Form, Meaning, and Use—structured the current study.

Considering that the development of a test battery to measure all aspects of vocabulary knowledge outlined by Nation (2013) was impractical (Ishii & Schmitt, 2009), the current Ph.D. project focused on four aspects of vocabulary knowledge: (a) word parts, (b) associations, (c) collocations, and (d) form and meaning. The study measured 46 Iranian university EAP students’ productive vocabulary knowledge of the words at the 1,000 word frequency level. One productive test of word parts, two productive tests of semantic associations (synonym & antonym, and superordination & subordination tests), one productive test of collocation, and four corresponding productive tests of form-meaning connection for the aforementioned tests were developed for the present research.

The results showed that while the participants had a strong performance on form-meaning connection and superordination and subordination, their knowledge of collocations was considerably lower. The results also showed that the participants’ performance on synonymy and antonymy, on association as a general term (synonym and antonym, superordination and subordination, and collocation altogether), and on word parts was not as strong as expected and was considerably lower than the maximum possible performance.

Together the findings indicate that while Iranian university students had the productive Meaning knowledge of the words at 1,000 level, they did not seem to have extensive Form knowledge of the same words, and their Use knowledge was limited. This assists in diagnosing areas of weakness and the degree to which instructional emphasis on high frequency words might improve their knowledge.