Authors: Godson Robert Mtallo (Department of Foreign Languages and Linguistics, University of Dar es Salaam, Tanzania), Gerald Kimambo, PhD (Department of Foreign Languages and Linguistics, University of Dar es Salaam, Tanzania)
Abstract: This study examined the relationship between the breadth and depth of vocabulary knowledge among Tanzanian learners who use English as a foreign language. It employed a convergent parallel mixed-methods design which simultaneously collected qualitative and quantitative data from a sample of 320 secondary school learners from Dodoma City and Chamwino District and eight English language teachers with at least five years of teaching experience. The study employed two different language tests, namely the New Vocabulary Levels Test and the Word Association Test, to collect quantitative information on the breadth and depth of vocabulary knowledge, respectively. It used semi-structured interviews with the selected English language teachers to obtain qualitative data to supplement the quantitative data. A Pearson correlation coefficient indicated a positive relationship between breadth scores and depth scores; as breadth scores increased, depth scores also increased. The results imply that the breadth and depth of vocabulary knowledge are like two sides of the same coin, which cannot be separated. Thus, the higher the learners’ performance in the breadth test, the higher their performances in the depth test. In this regard, it suffices to conclude that vocabulary use is part of vocabulary knowledge. The obtained results call for a comparative longitudinal study to trace the development of vocabulary knowledge among the compared groups over an extended period.