Abstract

Background: Vocabulary knowledge plays a fundamental role in second and foreign language learning, as it supports learners' reading comprehension, language use, and overall ability to communicate effectively. Purpose: This study examined the effect of AI-assisted cognitive vocabulary strategy instruction on vocabulary retention among Saudi male EFL undergraduate students. Methodology: The study employed a quantitative quasi-experimental one-group pre-test-post-test design with a delayed post-est. The participants were 36 Saudi male EFL undergraduate students enrolled in a 14-week reading and vocabulary-building course. During the intervention, AI was used as an instructional support tool to guide students through contextualized word explanations, noticing, semantic association, sentence production, review, and retrieval practices. Data were collected through a vocabulary pre-test, an immediate post-test, and a delayed post-test. Findings: The results showed statistically significant improvement across the three testing phases. Mean scores increased from the pre-test (M = 54.72, SD = 10.38) to the immediate post-test (M = 78.41, SD = 8.64) and remained relatively high in the delayed post-test (M = 73.86, SD = 9.21). A repeated-measures ANOVA indicated a significant difference across the three tests, F(2, 70) = 46.82, p < .001, with a large effect size. Originality: The study highlights the value of combining AI-assisted instruction with cognitive vocabulary strategies in the Saudi EFL context. Research implications: The findings suggest that AI can support vocabulary retention when it is integrated with clear teacher guidance and directed toward cognitive learning strategies.