Chernchok Soankwan

Development and Use of a Conceptual Survey in Introductory Quantum Physics

Conceptual surveys have become increasingly popular at many levels to probe various aspects of science education research such as measuring student understanding of basic concepts and assessing the effectiveness of pedagogical material. The aim of this study was to construct a valid and reliable multiple‐choice conceptual survey to investigate students’ understanding of introductory quantum physics concepts. We examined course syllabi to establish content coverage, consulted with experts to extract fundamental content areas, and trialled open‐ended questions to determine how the selected content areas align with students’ difficulties. The questions were generated and trialled with different groups of students. Each version of the survey was critiqued by a group of discipline and teaching experts to establish its validity. The survey was administered to 312 students at the University of Sydney. Using the data from this sample, we performed five statistical tests (item difficulty index, item discrimination index, item point biserial coefficient, KR‐21 reliability test, and Ferguson’s delta) to evaluate the test’s reliability and discriminatory power. The result indicates that our survey is a reliable test. This study also provided data from which preliminary findings were drawn on students’ understandings of introductory quantum physics concepts. The main point is that questions which require an understanding of the standard interpretations of quantum physics are more challenging for students than those grouped as non‐interpretative. The division of conceptual questions into interpretive and non‐interpretive needs further exploration.

The Effect of Interactive Lecture Demonstrations on Students' Understanding of Heat and Temperature: A Study from Thailand.

The purpose of this study was to investigate the effectiveness of Interactive Lecture Demonstrations over traditional instruction on university students’ understanding of heat and temperature. The participants were 327 first year undergraduate students from two science classes in two academic years from the same university in Thailand. One class was the experimental group taught using Interactive Lecture Demonstrations, while the other was the control group taught using traditional instructional methods. The Heat and Temperature Conceptual Evaluation test was administered to the experimental and control groups before and after instruction to evaluate student understanding. We found that the average normalized gain in the experimental group ( = 0.25) was higher than in the control group ( = 0.08). The results indicate that students taught using Interactive Lecture Demonstrations had a better understanding of heat and temperature concepts than students taught using traditional instruction.

Investigation of the use of rotating linearly polarized light for characterizing SiO 2 thin-film on Si substrate

This research is based on the Fresnels equations and the ellipsometric technique that investigate the sample of SiO2 thin-film on Si substrate. The investigation is made by a probing beam which is in the form of a rotating linearly polarized light generated by the polarizing Mach-Zehnder interferometer (pMZi). The detection of the changed polarization states of the incident light due to reflection on the sample surfaces led to a set of unique characteristics describing a thin-film substrate system in terms of ellipsometric parameters ψ and Δ. SiO2 thin-films were chosen to study because of their well known characteristics. The accuracy of measurements was confirmed by comparisons to calculated values derived from Fresnels equations and a standard instrument. The results clearly reveal a feasibility of using the rotating linearly polarized light produced by pMZi for a non-destructive characterization of the thin-film system.