Sarah Zöchling (2019 – 2023) Students’ types of interest in physics revisited
Fostering students’ interest in physics is an essential part of physics education and has been found to correlate with their achievement and career choices. One important past empirical study, the IPN interest study, introduced students’ types of interest in physics. Yet, past studies did not include modern physics content areas, such as particle physics, and mostly focus on the sex instead of other student characteristics, such as physics-related self-concept. Moreover, the IPN study did not describe how interesting different contexts are relative to each other within the students’ different types of interest. Therefore, physics education research is faced with three important questions, namely (1) into which different types of interest in physics can students be categorised while additionally considering particle physics as a modern physics content area, (2) how interesting are different contexts within these interest types, and (3) are the interest types described better focussing on physics-related self-concept as student characteristics compared to sex. This doctoral research project set up to provide evidence for answering these three questions by conducting two studies on physics education. In the first study an Instrument to measure students’ Particle Physics Interest (IPPI) was developed, since studies on the relationship between interest and other aspects of education, such as achievement and self-concept, require the use of psychometrically sound measurement instruments. The IPPI was developed using rating scale items that assessed different degrees of being interested in particle physics. A novel approach was suggested and applied to conducting a Rasch analysis for selecting items from an initial item pool in a clear, stepwise, and reproducible way. The IPPI was tested in student think-aloud interviews and validated in a field test with 99 German-speaking grade 9 students. Evidence supporting the content, construct, statistical, and fit validity of the IPPI was provided by a Rasch analysis. Overall, this first study led to the successful development of the IPPI and the conceptualisation of students’ interest in particle physics as a hierarchy of levels of interest in particle physics. Second, the main study was conducted, a cross-cohort study with German-speaking students aged 14 to 16 years (N = 1219). Students’ interest in mechanics and particle physics was assessed using the instrument to measure mechanics interest from the IPN study and the IPPI. In addition, different student characteristics, such as their physics-related self-concept, sex, and previous experience with the content areas in school, were assessed. The main aim of this study was to investigate students’ types of interest in physics and their association with different student characteristics. The collected data on students’ interest and self-concept, was analysed using mixed Rasch models to unveil qualitative differences in the assessed constructs between different groups of students. Moreover, when interpreting the results of the mixed Rasch analyses, differential item functioning as well as students’ response styles were considered. The main study showed that most students can be categorised into one single type of interest in both content areas (86% of the students in mechanics and 79% of the students in particle physics, respectively). For both content areas, students of this first interest type are only interested in physics content set in certain contexts, for example, the context “one’s own body”. For mechanics, the second type of interest comprises students who are relatively more interested in physics relating to the motion of cars (14% of the students); and for particle physics, the second type of interest was referred to as the ‘particle physics lovers’ reflecting their relatively higher interest in particle physics as a content area and as a scientific endeavour (21% of the students). It was found that whether students belong to one or the other type of interest in both content areas can best be described with a model comprising both their degree of physics-related self-concept and their sex. The conceptualisation of interest as a hierarchy of students’ levels of interest, originally introduced for particle physics only in the first study, was successfully applied to describe the relative interestingness of different contexts for the first type of interest (i.e. the vast majority of students) in both content areas. Hence, the conceptualisation was suggested as a guideline for physics in general and named “Hierarchy Of students’ Levels of Interest in Physics” (HOLIP). The study also showed that previous experience in school with mechanics and particle physics, respectively, is correlated with students’ interest in this particular content area for the first type of interest. In sum, the doctoral research project led to the successful development of the IPPI (Instrument to measure students’ Particle Physics Interest). It showed that most students can be categorised into one single type of interest in physics and that their interest can be described using the HOLIP (Hierarchy Of Levels of Interest in Physics). The results of this doctoral research project have implications for both physics education and physics education research. Educators, such as teachers, can use the HOLIP as a tool to develop learning activities that are interesting for students with different degrees of interest in physics and physics-related self-concept. For physics education research the first study suggests a novel approach to conducting a Rasch analysis for selecting items from an initial item pool in a clear, stepwise, and reproducible way. The main study supports conducting a mixed Rasch analysis to unveil qualitative differences in an assessed construct, such as interest and self-concept, between different groups of students. Moreover, it provides a strong case for considering differential item functioning as well as the students’ response styles when interpreting the results of a mixed Rasch analysis.
University of Göttingen, Prof. P. Klein & Prof. A. Müller (University of Geneva)