Developing a situational interest scale for Indonesian young learners: beyond academic scores in primary EFL classrooms

Situational interest (SI) significantly influences student engagement, yet validated instruments tailored to primary English as a Foreign Language (EFL) classrooms remain limited. This study aimed to develop and validate an SI measurement tool for young EFL learners in Indonesia. Conducted over one academic semester (6 months), the two-phase mixed-methods study began with a qualitative analysis of 412 reflective journal entries from 103 fifth-grade students to identify key dimensions of SI. Three core factors emerged: lesson interest, cognitive-affective engagement, and self-learning fulfilment. Based on these, a ten-item instrument was developed and administered to 450 students across Grades 3 to 6 at the same bilingual primary school, yielding a 100% response rate. Confirmatory factor analysis demonstrated strong model fit (CFI = 0.978, TLI = 0.970, RMSEA = 0.070), and internal consistency was confirmed (lesson interest: α = 0.822; cognitive-affective engagement: α = 0.920; self-learning fulfilment: α = 0.867). The validated instrument offers a practical tool for assessing and enhancing situational interest in Indonesian primary EFL classrooms and provides empirical guidance for interest-based instructional design.