Biology teachers' professional transformation through research-based teaching material development: Building understanding, self-confidence, and teaching motivation.

Research-based teaching has been widely recognized as a pedagogical approach that integrates scientific inquiry, empirical evidence, and academic culture into classroom practice. However, many Biology teachers still lack the understanding, confidence, and motivation to develop and implement research-based teaching materials. This study aims to examine the effect of training in preparing research-based teaching materials on teachers' understanding, confidence, and motivation in teaching Biology, and to explore teachers' responses to the application of these materials in classroom practice. A mixed-method sequential explanatory design was used, involving 46 high school biology teachers in Tulungagung, East Java, Indonesia. Quantitative data were collected using pretest-posttest instruments and analyzed using N-gain and Wilcoxon tests. In contrast, qualitative data were collected through in-depth interviews and analyzed using Miles and Huberman's interactive models. The results revealed a significant improvement in teachers' understanding, confidence, and motivation after training, with a statistically significant difference between pretest and posttest scores (p < 0.001). Qualitative findings show that teachers are successful in applying research-based teaching materials across a variety of formats and contexts, encouraging more contextually relevant, evidence-based, and meaningful Biology learning. Teachers also reported increased student engagement, curiosity, and analytical thinking. Despite these positive results, the challenges associated with limited time, infrastructure, and access to research resources remain clear. Overall, the study shows that research-based training in preparing teaching materials can effectively enhance teachers' professional capacity and promote a research-oriented teaching culture, provided it is supported by ongoing institutional and systemic support.