碩士 國立彰化師範大學 數學系所 102 This study aims to investigate the incentives that make a teacher change teaching methods and the factors of keeping changing by observing an experienced math teacher who used to adopt traditional teaching methods. The result can be used to help promote Teachers’ Professional Development in the future. For research purposes, the adapting of case studies will be used; using interviews, observation, the video recording of the teaching experiment, the feedback sheet from students,, the reflection notes on teaching, data analysis, and other methods to gather information. The gathered information will further be organized, analyzed, and categorized in order to fully understand the incentives and factors that make experienced teachers that adopt traditional teaching methods change their teaching methods. Based on the result of the research and data analysis, two conclusions of this study are drawn as follows: First, the conflicts between teaching beliefs and the ineffectiveness in teaching can