My study explores the characteristics of remote performance feedback that professional examiners working in the Oxford, Cambridge & RSA (OCR) awarding body communicate to each other. Drawing on sociocultural theories, I argue that this interaction possesses learning potential because between-professional communication supports the development of participants’ reasoning through the alignment of culturally appropriate collective thinking. My data consists of 991 feedback messages that were captured during two examination sessions (between May and July 2014, and between May and July 2015). These remote interactions (either email or telephone) involved three senior examiners and 27 examiners. These feedback interactions have an important quality assurance function as they help to ensure that the examiners carry out marking practices to an agreed standard. My research explores two interlinked research questions: ‘What are the characteristics of examiner feedback?’ and ‘What are the characteristics of effective examiner feedback?’ For the first research question I develop a methodology that extends the Sociocultural Discourse Analysis (SCDA) approach developed by Neil Mercer; I call this approach Augmented Sociocultural Discourse Analysis (ASCDA). My methodology allows me to investigate the features of interaction at both a particular and a general level, and clusters my analysis into four specific feedback discourse themes: feedback content, the development of discourse over time, evidence of joint intellectual action within feedback, and the impact of feedback. In order to address the second question I hypothesise that effectiveness relates to how feedback features support or undermine examiners’ common ground building. I synthesise the findings from these analyses to consider the lessons for examiner practice in particular, and for other professional feedback practices more generally. Taken together, these analyses suggest that feedback-giving is an intellectually challenging process. My analyses also suggest that this complexity involves the participants establishing and maintaining an Intermental Development Zone through their feedback communication, and that this entails them manipulating discourse features whilst simultaneously attending to a variety of contextual features of the professional environment.