Analyzing Students’ Conceptual Understanding in Scientific Writing Using One-Parameter Logistic Item Response Theory

Abstract

This study investigates the comparative impact of Project-Based Learning (PjBL) and STEM-integrated Project-Based Learning (PjBL-STEM) on students’ creativity in continental food processing classes among 12th-grade culinary students at SMK N 1 Bawen. Employing a quasi-experimental design with a non-equivalent control group pretest-posttest structure, the study involved a sample of 72 students selected through simple random sampling from a total population of 108. Data were collected using structured classroom observation instruments, which were validated through expert judgment and demonstrated strong content validity and reliability (Cronbach’s Alpha > 0.80). The data analysis was conducted using independent samples t-test, preceded by normality and homogeneity testing. The results revealed a statistically significant difference in creativity between the two groups (p = .001), indicating that the PjBL-STEM model led to superior learning outcomes. Students taught using the PjBL-STEM model achieved a higher average post-test score (M = 76.03) compared to those taught using PjBL alone (M = 69.11). These findings suggest that integrating STEM into project-based learning effectively enhances students’ creativity in vocational culinary education, offering promising implications for instructional design in 21st-century skills development.