The focus of this study was to identify various reviewers' viewpoints of educational events by examining type of knowledge shared by reviewers for quality assurance during lesson study. I present the overview of our Peer Review Process Project and report on five pilot studies conducted during the 2009 spring and autumn terms. The successive trials revealed the following three points: (1) the lecture summary content differed between reviewers depending on their specialty and teaching experience, (2) reviewers with the similar specialty to the lecturer suggested how to teach the contents more effectively than a faculty developer, (3) the lecturer being evaluated accepted the comments with respect to lecture content and methodology in lesson study after class observations.