...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...

... through the interconnected ideas of “became, being and becoming”. Findings The editorial argues that koshi should not be understood merely as outside experts or knowledgeable others who advise teachers. Instead, the studies in this special issue portray koshi as professionals who learn through ongoing...

...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...

..., “knowledge is constructed in response to social interactions through social negotiation, discourse, reflection, and explanation” (Rock and Wilson, 2005 , p. 79). Under social constructivism, a knowledgeable other (KO) scaffolds teachers in the LS group to develop their practice knowledge. Thus, the concept...