Introduction Although the practicum is generally accepted as a core element in teacher preparation programmes, the assessment of student teachers’ competence during practicums appears to be particularly problematic as making judgments about complex performances, such as teaching, is a sophisticated process. As with any form of assessment, judgments are made against some criterion or normative standard, and this judgment must ultimately involve some implicit or explicit understanding of what constitutes good teaching (Porter, Youngs, & Odden, 2001), which in itself is a contested construct. In this 2-year research project, Social Judgment Theory (Hammond, Rohrbaugh, Mumpower, & Adelman, 1977) was used to better understand judgments of “readiness to teach”. Social Judgment Theory