Abstract This exploratory study examines how Control of Variables Strategy (CVS) sub-skills develop among high school students through Inquiry-Based Learning (IBL) activities in physics. It specifically assesses students' understanding of four CVS sub-skills (Planning, Identifying, Interpreting, and Understanding) as they engage in Confirmation, Structured, and Guided inquiry activities. A total of 22 students from 10 and 11th grades participated in this four-month study. An exploratory Rasch analysis offered initial insights into how the difficulty levels of each CVS sub-skill changed over the instructional sequence, though interpretations are limited by methodological constraints such as a small sample size (N = 22) and ceiling effects observed in students’ responses. The results show initial signs of gradual improvement across all CVS sub-skills, with Understanding demonstrating the largest normalized Hake gain and the most significant overall progress, while Planning consistently remained the biggest challenge for students. After the Guided Inquiry phase, students displayed the clearest qualitative gains in Planning and Identifying, suggesting potential benefits of increasing student autonomy. Despite the study’s limitations, this research provides valuable initial insights into how structured and guided inquiry can gradually enhance students' scientific reasoning skills.
Gkagkas et al. (Tue,) studied this question.