The central question in this thesis is How do participants in the practicum interact in order to evaluate teaching practice? This question has been posed for several reasons: 1. The practicum is a crucial part of teacher education and teacher socialisation; 2. Little is known about the nature of student teacher learning during the practicum; 3. Much of what happens during practicum interactions is taken for granted, and needs to be made explicit in order to fully understand how student teachers learn and what it is important for them to know. In order to investigate this question this study examines the interactions between student teachers and their supervising teachers in post lesson conferences. These conferences are a site in which practicum participants evaluate teaching practice and in which values, beliefs and knowledge about teaching in the context of the classroom and the practicum are produced and reproduced. To obtain data on the ways in which participants interact in post lesson conferences tape recordings of conferences and interviews with participants have been collected and analysed. Three quite different cases are presented to show a spectrum of evaluative styles and interactions. In each case the language of the post lesson conferences is explored. A particular concern in the thesis has been to consider the ways in which the linguistic choices of the participants express their subjectivities as well as reflect the cultural and institutional context in which the post lesson conferences were located. In order to achieve this the study draws upon theoretical perspectives concerned with social practice, language and meaning. Fundamental to any evaluative interaction is its purpose, the relationship between the participants and the construction of the evaluative criteria. This study has sought to identify those routines that are a common part of and that underpin the purpose of evaluative interactions in post lesson conferences. By considering the differences between the interactions in each case, this research concludes that the degree of symmetry in the participants' evaluative relationship and the extent to which the evaluative criteria are made explicit are critical to the authority that student teachers have to negotiate their understandings, reflect on their practice and take responsibility for their own learning. The three cases provide a dynamic account of the evaluative process, and a more comprehensive account than has hitherto been provided in much of the literature. They also generate suggestions for future research in this important area of teacher education.