...Jongsung Kim; Shirley Tan; Ban Heng Choy Purpose This editorial introduces the special issue on koshi (講師) in communities of lesson studies and explores how individuals came to assume this role (became), how they experience it in practice (being) and how they continue to develop it throughout...

...Jongsung Kim; Hiromi Kawaguchi; Nariakira Yoshida Purpose This study explores how koshi, knowledgeable others in Japanese lesson study, learn to support teacher learning by examining their own facilitation practices. Although koshi play a key role in sustaining lesson study, relatively little...

...João Pedro da Ponte Purpose The aim of this article is to analyze the features of the role of the facilitator in leading post-lesson discussions in lesson study in the contextual conditions of Portugal, identifying points of contact and differences regarding the role of koshi in Japan. Design...

...David Sekao Purpose Lesson study (LS) is a collaborative teacher development practice, and one of the key attributes thereof is the involvement of the external knowledgeable other (koshi). Despite well-documented evidence that LS improves the craft of teaching, the entrenched concept...

...Wanty Widjaja; Aylie Davidson; Felicity Ames Purpose This paper aims to examine the self-study of three Koshi in analyzing lesson plans (LP) to prepare for the “final comments” for novice pre-service primary teachers in Australia. Analyzing LP is a critical step in preparing “final...

...Eric C.K. Cheng Purpose This study aims to explore the roles of Koshi within the Learning Study framework, a Hong Kong adaptation of Lesson Study guided by variation theory. It examines Koshi’s pathways to becoming mentors, facilitators and critical friends, their day-to-day responsibilities...

...Andrew J. Pereira; Yanping Fang; Ken Mizusawa; Carina Hui Ling Koh; Brenda Lee Purpose This paper explores how pedagogically productive talk (PPT) and reflexive practices foster equitable and dialogic interactions within teacher–Koshi partnerships during the Lesson Study (LS) process...