Pre-Class Tutorial (PCT): an instructional strategy to improve pre-service physics teachers' understanding about P-V-T-S diagrams in thermodynamic course

The Pre-Class Tutorial has been used to successfully improve the deep conceptual understanding and skills to draw and interpret the P-V-T-S diagrams in Thermodynamic Courses. This study was motivated by the previous research findings that students encounter the lack of conceptual understanding to draw and interpret the P-V-T diagrams to describe thermal process and Cycles of Ideal Gas. The analysis of the academic responses at written test shows that some of the students' conceptual difficulties as follows. First, the biggest difficulty in each P-V, P-T, V-T and T-S diagram is to draw an adiabatic process. Second, the percentage of students who answer the P-V diagram correctly is higher than those who answer the P-T, V-T and T-S diagram. Third, Students prefer understanding thermal processes with their unique characteristic, such as isobaric with constant pressure, isotherm with constant temperature, and isochoric with volume constant. Finally, the lack of understanding the concept of P-V-T-S diagram also affects students' understanding of various thermal cycles. Based on these findings, we developed the pre-class tutorial that facilitates students either to construct their own concepts to draw and interpret the P-V-T-S diagram. The descriptive method was used to involve 88 third-years students of Physics Education Department. The increased conceptual understanding was identified from the average of students' achievement score on the instrument test. The findings showed that the use of pre-class tutorial effectively improves students' conceptual understanding of the draw and interpret the P-V-T-S diagrams to describe thermal process and Cycles.