%0 Journal Article %T Tutorial teaching assistants in the classroom: Similar teaching behaviors are supported by varied beliefs about teaching and learning %A Renee Michelle Goertzen %A Rachel E. Scherr %A Andrew Elby %J Physical Review Special Topics. Physics Education Research %D 2010 %I %X As part of a long-term program to develop effective, research-based professional development programs for physics graduate student teaching assistants (TAs), we first identify their current classroom practices and why they engage in these practices. In this paper, we identify a set of teaching practices we call ¡°focusing on indicators,¡± which occurs when TAs use signs such as key words or diagrams as evidence that students understand the target idea; these indicators are more superficial than a detailed explanation. Our primary finding is that although the three TAs discussed here share a common behavior, the beliefs and motivations that underlie this behavior vary. We argue that TA professional development focused on changing these TAs¡¯ focus-on-indicator behavior is unlikely to be effective. Instead, responsive TA professional development will need to address the TAs¡¯ beliefs that guide the observed classroom behavior. %U http://link.aps.org/doi/10.1103/PhysRevSTPER.6.010105