Abstract
<p>The rapid integration of Generative AI (GenAI) into education necessitates the urgent enhancement of teachers' Pedagogical Content Knowledge (PCK). This study investigated the efficacy of an intensive 8-hour professional development (PD) program on five core AI-PCK components and analyzed the difference in learning gains between experienced and pre-service teachers. Methodology: A quasi-experimental pretest-posttest design was utilized with 163 teachers and pre-service teachers. Data were collected using a researcher-developed questionnaire and analyzed using paired and independent t-tests. Findings: 1. The PD program was significantly effective across all five AI-PCK components (p &lt; 0.001), with the highest effect size observed in the Rubric Assessment component (d = 2.19) and an overall effect size of d = 2.36. 2. Pre-service teachers demonstrated a statistically higher overall PCK learning gain compared to experienced teachers (p = 0.033). Conclusion: The intensive PD model is highly efficacious for rapid AI-PCK enhancement. However, the difference in learning gains highlights the need to integrate AI-PCK components into core teacher training curricula and to design specialized, extended PD programs to address the unique learning needs of experienced educators.</p>