This study aims to: 1) develop a valid instrument to measure students' scientific literacy skills; 2) describe the scientific literacy profile of students; and 3) identify factors affecting students' scientific literacy skills. Scientific literacy is defined as the ability to understand, apply, and make decisions based on scientific knowledge, which is increasingly crucial amidst the complexity of global challenges.

The research involved the development and validation of instruments to ensure their reliability in measuring scientific literacy. These findings can serve as a foundation for developing more effective science learning methods and supporting the enhancement of scientific literacy among prospective teachers. The instrument used consists of 18 items designed to assess various aspects of scientific literacy. The evaluation process involved validation by three field experts.

Results showed that 18 items were deemed valid, with a Validity Coefficient Index (CVI) of 1, while four items required revision. Reliability testing using Cronbach’s Alpha yielded a score of 0.945, indicating excellent internal consistency. The two-parameter Item Response Theory (IRT) analysis revealed that most questions have adequate discrimination power and moderate difficulty levels, although some items need improvement. Measurement results indicate that 54% of students fall into the low category, while 46% are in the high category of scientific literacy. The study also explores the influence of the education system and motivation on scientific literacy, with both factors contributing significantly to 51.9% of the variance. Motivation showed a greater influence than the education system. This research highlights the need for curriculum adjustments and interactive learning methods to enhance scientific literacy. Problem-based or project-based approaches are recommended to bridge theory with real-world applications. These findings are crucial for educational policy development supporting 21st-century competencies, providing strategic insights for improving science education quality in higher education, particularly for prospective elementary school teachers.