This study aimed to explore the facts of what knowledge student teachers acquired/developed through teaching practice in schools, along with the primary factors behind this. First, a framework for interpreting teacher knowledge was stipulated through analysis of previous studies. Next, one teaching-practice group that trained student teachers in Lower Secondary School B Attached to National University A was selected to perform field work as a case. And also, we observed lessons, participated in reflective meeting/conference, and conducted interview survey. Then, the data that was gathered through the interview survey was analysed qualitatively with SCAT (Otani, 2008b, 2011).

The results gained through analysis were classified from three viewpoints: the influence of the mentor, observations on other student teachers’ lessons, and reflection on their own practice. Discussing with the model of teacher professional knowledge and skill by Gess-Newsome (2015), the followings were pointed out: (1) knowledge base is acquired/developed by capturing reflectively their own classroom practice, reflective meeting/conference and observations of other student teachers based on their view of (science) lessons, which is begun to construct through educative mentoring and observations lessons by the mentor; and (2) collaboration with other student teachers enables to conduct teaching practice more reflectively.

This article translated into Japanese is published in the journal Gakushu Shisutemu Kenkyu, Vol.3.