The Effect of Multimodal Instruction on Vocabulary Learning and Retention in Iraqi EFL Classrooms

Abstract

Vocabulary knowledge remains a fundamental component of second language competence, yet Iraqi EFL learners face considerable challenges in acquiring and retaining lexical items due to limited exposure to authentic English and predominant reliance on traditional text-based instruction. This quasi-experimental study examined the impact of multimodal instruction on vocabulary learning and retention among 60 intermediate Iraqi EFL learners randomly assigned to an experimental group (n = 30) receiving instruction integrating visual, auditory, and textual materials, or a control group (n = 30) taught through conventional text-based methods. While extensive international research has documented the benefits of multimodal approaches for vocabulary acquisition, empirical evidence from the Iraqi EFL context, characterized by resource constraints, examination-driven pedagogy, and limited authentic language exposure, remains conspicuously absent. This study addresses this gap by drawing upon Dual Coding Theory (Paivio, 1971), Cognitive Theory of Multimedia Learning (Mayer, 2014), and Depth Processing Hypothesis (Craik & Lockhart, 1972) to investigate whether multimodal instruction yields superior learning outcomes in this under-researched context. Both groups completed a 30-item vocabulary test before intervention, immediately after, and two weeks later. One-way ANCOVA controlling for pre-test scores revealed that the multimodal group demonstrated significantly better performance on both the immediate post-test (F(1,57) = 40.62, p < .001, η²ₚ = .413) and the delayed post-test (F(1,57) = 62.31, p < .001, η²ₚ = .521), with large effect sizes indicating substantial practical significance. These findings empirically confirm that the simultaneous presentation of written definitions, visual illustrations, audio recordings, and video clips creates redundant memory traces and facilitates deeper semantic processing, thereby enhancing both initial vocabulary acquisition and long-term retention. The results provide strong theoretical validation for multimodal learning principles in a resource-limited EFL context and offer practical guidance for curriculum developers, material designers, and classroom practitioners seeking evidence-based strategies to improve vocabulary instruction in Iraqi educational settings.