<![CDATA[This study aimed to develop and validate the Students’ Learning and Assessment Experience of Content and Procedural Knowledge (SLAE-CPK) instrument, designed to capture high school students’ experiences in learning and assessment related to content and procedural knowledge in biology education. Grounded in the PISA 2025 Science Framework and the principles of experiential learning and social constructivism, the instrument responds to gaps in Indonesia’s science education system, where assessment practices often emphasize conceptual understanding while neglecting procedural skills. Using a Research and Development (RD) approach, the instrument underwent expert validation, empirical testing with 103 students, and Rasch model analysis to ensure its validity, reliability, and construct alignment. The final version comprises three core aspects (learning experience, assessment experience, and post-assessment experience) each addressing both content and procedural knowledge dimensions. The instrument demonstrated strong internal consistency (Cronbach’s α = 0.91) and fit indicators, supporting its utility in both formative assessment and reflective pedagogical practice. Beyond measurement, qualitative findings revealed that the instrument may serve as a metacognitive tool that fosters learner autonomy and enhances teacher-student dialogue. While the instrument shows promise for improving science instruction in Indonesia, further research is recommended to explore its cross-disciplinary, cross-cultural, and longitudinal applicability.]]>
