Motivation STEM degrees offer diverse opportunities in forward-looking industries, yet many students perceive them as difficult. In Chemistry, Organic Chemistry (OC) is often described as a ‘gatekeeper’ course due to its complex concepts, mechanistic reasoning and multiple forms of representation (Graulich, 2025; O' Dwyer & Childs, 2017). These challenges are reflected in low enrolment and high dropout rates, which have been the focus of previous research (e.g.,Walpuski et al., 2021). While such studies provide valuable insights into students’ perceptions of STEM degree programs, they rarely consider the perspective of university instructors, those who plan, enact and reflect on teaching. As highlighted in Hattie's (2009) meta-analysis, teachers and instructors have a substantial impact on student achievement, underscoring the need to examine their professional knowledge for teaching, commonly referred to as Pedagogical Content Knowledge (PCK), in more detail.
Methods
Systematic Literature Review
This project combines three complementary approaches to gain insights into organic chemistry instructors’ PCK. First, a systematic literature review was conducted to identify existing research and remaining gaps concerning the analysis and development of instructors’ PCK in chemistry. The review revealed a particular need for objective, quantitative measures of PCK in the university context.
Qualitative Think-Aloud Study
To structure organic chemistry instructors’ PCK, four written vignettes covering central concepts from introductory organic chemistry will be developed. These vignettes are designed to contextualize instructors’ teaching-related reasoning in terms of different learner groups and various teaching formats, such as lectures, tutorial classes, and laboratory courses. They will be used in a think-aloud study to gain qualitative insights into the structure, depth, and interconnectedness of different PCK facets.
Quantitative Study
In the subsequent quantitative phase, the same vignettes will be used to generate assessment items based on the qualitative think-aloud data. Depending on the nature of the elicited responses, these items may take open or closed formats. The resulting instrument will be administered internationally to enable objective, quantitative comparisons across different countries and higher education contexts. The data will allow for a quantitative description of instructors’ PCK and support the statistical validation of PCK constructs in the university context, using Item Response Theory (IRT) with Partial Credit Modeling (PCM).
Results
Outcomes
Systematic Literature Review (Completed)
The systematic literature review identified research gaps that underscore the need for a valid, objective, and quantitative instrument to assess instructors’ PCK across diverse teaching contexts. Previous research on instructors’ PCK has predominantly relied on qualitative methods and has often been conducted in non-specific contexts, both in terms of discipline and teaching situations (e.g., laboratory courses). Similarly, studies aiming to foster PCK-related knowledge have typically used either qualitative approaches, such as interviews, or evaluative questionnaires in which participants rate the usefulness of training interventions. This quantitative blind spot highlights the necessity of developing a robust, quantitative test instrument.
Qualitative Think-Aloud Study
The second study will generate discipline‑specific evidence on instructors’ PCK mapped to the facets proposed by Magnusson et al. (1999). Based on this evidence, performance indicators for instructors’ PCK will be developed, operationalized using the competence levels described by Schiering et al. (2022). These indicators are expected to provide initial insights into the structure, depth and interconnectedness of instructors’ PCK and will serve as the basis for developing assessment items for a subsequent quantitative study. Vignettes covering core topics in undergraduate organic‑chemistry courses, aligned with the RCM teaching cycle (plan–teach–reflect; Carlson et al., 2019), will serve as the primary basis for eliciting instructors’ PCK.
Quantitative Study
Results from the qualitative study will serve as the basis for the quantitative assessment of instructors’ PCK. Items derived from the Study‑2 vignettes will be adapted into short‑answer (constructed‑response) or closed formats, depending on the qualitative findings, and used to quantitatively describe instructors’ PCK levels. Data will be analyzed using Item Response Theory, with the Partial Credit Model applied to ordered polytomous items where sample size permits. The instrument will be administered internationally to enable cross‑national comparisons, subject to adequate sample sizes.
Key References
- Carlson et al. (2019). The Refined Consensus Model of Pedagogical Content Knowledge in Science Education.
- Graulich, N. (2025). The tip of the iceberg in organic chemistry – revisited.
- Hattie, J. (2009). Visible learning: A synthesis of over 800 meta-analyses relating to achievement.
- Magnusson et al. (1999). Nature, Sources, and Development of Pedagogical Content Knowledge for Science Teaching.
- O' Dwyer & Childs (2017). Who says Organic Chemistry is Difficult? Exploring Perspectives and Perceptions.
- Schiering et al. (2022). A proficiency model for pre‐service physics teachers' pedagogical content knowledge (PCK)—What constitutes high‐level PCK?
- Walpuski et al. (2021). Chemie, Sozialwissenschaften und Ingenieurwissenschaften: Studienerfolg und Studienabbruch.
