The Impact of Convergent and Divergent Tasks on Iranian EFL Learners’ Vocabulary Breadth and Depth
Abstract
Vocabulary knowledge is recognized as a central component of proficiency, influencing learners’ performance in reading, writing, listening, and speaking. To this end, the present study aimd at analyzing the significant impact of convergent and divergent tasks have a on the breadth and depth of vocabulary knowledge among 80 Iranian EFL learners, and whether one task type proves more effective than the other in promoting balanced lexical development.Employing a quasi-experimental, pretest–posttest design, two groups received task-based instruction over a ten-session treatment period, after which performance on the post-tests was compared to the pre-test results. The independent variable was the task type (convergent vs. divergent), while the dependent variables were vocabulary breadth – operationalized through the Vocabulary Levels Test (VLT) – and vocabulary depth – assessed through the Word Association Test (WAT). The results of paired-samples t-tests indicated that both the Convergent (p = .000 < .05) and Divergent (p = .000 < .05) groups showed statistically significant improvments from pre-test to post-test on the Vocabulary Levels Test. The results also revealed statistically significant difference between groups, t(78) = 3.87, p = .000 < .05, with a large effect size (d = 0.86). Learners engaged in Convergent tasks outperformed those in Divergent tasks on the VLT, indicating that the Convergent task structure significantly enhanced vocabulary breadth. Both analyses showed significant (p = .000 < .05) differences, indicating that task type had a statistically significant effect on learners’ performance in both vocabulary dimensions. The effect size was moderate for breadth (η² = .16) and large for depth (η² = .23), implying that Divergent tasks exerted a stronger influence on the depth of lexical learning, while Convergent tasks had a more modest yet substantial effect on breadth. Running ANOVA analysis, the between-group comparisons showed that convergent tasks were more effective in promoting vocabulary breadth, whereas divergent tasks were more effective in promoting vocabulary depth.Therefore, vocabulary development is optimized when convergent and divergent creativity are balanced, enabling learners to develop both the breadth and depth of lexical knowledge required for flexible and effective language use.
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Copyright (c) 2025 Hamed Torabi Sheykh Ahmadloui (Author); Ali Asghar Yousefi Azarfam; Mahnaz Saeidi (Author)
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