<![CDATA[Vocabulary mastery plays an important role in English as a Foreign Language (EFL) learning, yet evidence comparing vocabulary notebooks with dictionary-based instruction while considering students' learning motivation remains limited. This study investigated differences in vocabulary achievement between students taught using an English Vocabulary Notebook (EVN) and an Indonesian-English Dictionary (IED), while examining the role of learning motivation. A quasi-experimental pre-test-post-test study was conducted with 71 eighth-grade students from two intact classes in one Islamic junior high school. Two purposively selected classes were assigned to different instructional media, with one class using the EVN and the other using the IED. The intervention consisted of two instructional meetings between the pre-test and post-test. Students' learning motivation was measured using a questionnaire administered before the intervention, and students were ranked according to their total motivation scores, with those in the upper half classified as highly motivated and those in the lower half classified as low motivated. Post-test vocabulary scores were analyzed using a two-way ANOVA after the assumptions of normality and homogeneity of variance were satisfied. Both instructional groups demonstrated higher post-test than pre-test vocabulary scores. The analysis revealed significant main effects of instructional media, F(1, 67) = 92.16, p < .001, ηp² = .725, and learning motivation, F(1, 67) = 17.23, p < .001, ηp² = .330. No significant interaction between instructional media and learning motivation was found, F(1, 67) = 7.041, p = .112, ηp² = .166, indicating that the study did not provide sufficient statistical evidence that the relationship between instructional condition and vocabulary achievement differed between the two motivation groups. These findings indicate that significant differences were observed between the two instructional conditions, although the groups differed in their baseline vocabulary achievement. However, because instructional media were assigned to intact classes rather than randomly to individual students, the findings should be interpreted with appropriate caution when considering causal inferences.]]>
