Unraveling TPACK: Investigating the inherent structure of TPACK from a subject-specific angle using test-based instruments

Against the backdrop of digitalization, it is imperative to provide pre-service teachers with adequate training opportunities to foster their professional knowledge regarding technology integration in teaching-learning scenarios. However, to date, only limited insights into the empirical nature of such knowledge – often subsumed under the term Technological Pedagogical and Content Knowledge (i.e., TPCK) – are possible given the heterogeneity of prior research investigating the empirical relationship between different knowledge components. This heterogeneity is likely due to the predominant use of self-reports in previous studies. Against this background, the present study pursued two goals. The first goal was to investigate the empirical nature of TPCK among pre-service teachers, utilizing test-based instruments to explore TPCK's nature from a subject-specific angle, that is, its relationship with Pedagogical Content Knowledge (PCK) and Technological Knowledge (TK). Given the widespread use of self-reports, the study's second goal was to examine the relationship between test-based and self-reported TPCK, exploring possible associated factors (e.g., pre-service teachers' gender, prior experience in teaching with technologies in school, or metacognitive accuracy) that may explain why both measures are linked only weakly. Findings reveal that both PCK and TK statistically predicted TPCK to a similar extent highlighting the integrated nature of TPCK. The relationship between test-based and self-reported TPCK was moderated by pre-service teachers' metacognitive accuracy, but not by their gender or prior experience. Together, these insights offer valuable guidance for refining teacher training regarding effective technology integration by indicating the need to target not only PCK and TK but also TPCK.