<b>Trends in Professional Development of Mathematics Teachers Using Topic Modeling: A Scoping Review </b><b></b>

Professional development for mathematics teachers is a prerequisite for effective student learning. This study conducted a topic modeling analysis of 1,330 articles on the professional development of mathematics teachers published over 20 years from 2004 to 2024. As a result, ten topics related to the professional development of mathematics teachers were identified. These topics are popular research areas that have received a lot of attention from researchers during this period. To track trends in the field, a time-series regression analysis and annual trends in topic proportion were also examined. The 10 topics exhibited different research trends, including increasing, decreasing, and stable trends. The three topics Assessment, Technology, and Lesson reflection and Noticing emerged as hot topics that showed a significant increase in research interest during the period. The interest of researchers focused on the 10 topics varied depending on the year, but the studies were continuously conducted on most of them as time progressed. Based on these findings, this study suggested the current state and future directions in this field.