This study aims to develop a valid and reliable achievement test for astronomy topics incorporated into the 5th and 6th-grade science curriculum, specifically aligned with the Türkiye Century Education Model. Adopting a quantitative research design, the study utilized a relational survey model. Data were collected during the 2025–2026 academic year from a sample of 422 middle school students across three different districts in Türkiye. To ensure content validity, a specification table was developed and validated through expert review. Subsequently, item difficulty indices, upper-lower group mean comparisons, and item–total correlation analyses were performed. The internal consistency of the test, as measured by the KR-20 coefficient, was .859. Corrected item–total correlations ranged from .274 to .480, demonstrating that the items possess a satisfactory level of discriminative power. The finalized Astronomy Achievement Test (AAT), comprising 28 items, stands as a valid and reliable assessment tool that addresses a significant gap in the national science education literature and provides a contemporary framework for astronomy education.
Konakcı et al. (Tue,) studied this question.