Developing STEM-based assessments for prospective mathematics teachers the requires systematic identification of challenges, especially in planning, implementation, and STEM integration. Previous studies have shown the lack of instruments to map these barriers holistically, especially in Indonesia. This study aims to test the content validity of the STEM Challenges in Assessment Scale (SCiAS) instrument as a measurement tool for prospective teachers’ challenges in four indicators: assessment planning, assessment implementation, valid and reliable assessment, and STEM assessment integration. Content validation was conducted involving three experts in STEM education and learning evaluation. 22 out of 26 items achieved a perfect Item-Content Validity Index (I-CVI) score. Two items (I-CVI 0.67) were revised based on qualitative feedback to clarify the context of multidisciplinary integration and technology access challenges. The Scale-Content Validity Index (S-CVI/Ave) score of 0.92 confirms the instrument meets high validity standards. Experts emphasised the importance of this instrument in measuring the gap between STEM assessment theory and practice. The instrument validates teacher candidates’ challenges in four critical indicators of STEM assessment. This instrument can be the basis for developing teacher training to improve competencies in planning, implementing, and integrating valid assessments. Its implementation will support sustainable quality education through holistic STEM assessment practices.
Sari et al. (2025) studied this question.