Comparing shifts in TA comfort with content and weekly preparation in reformed intro physics labs

Across the United States, Introductory Physics Labs are typically broken into multiple sections often taught by graduate Teaching Assistants (TAs). Undergraduate students serving as lab TAs in a similar capacity to graduate TAs, as is happening at the University of Colorado Denver (CU Denver), is an understudied population. As part of a larger project studying the transformation and efficacy of the reformed Introductory Physics Labs at CU Denver, we seek to understand how the TAs prepare. We have designed weekly surveys for the TAs and implemented them over multiple semesters. The surveys probe changes to self-reported TA comfort throughout the week; our goal is to understand the effects of 1) the preparatory meetings and 2) in class teaching each week and over the course of a semester. In this work, we present a preliminary analysis of these data over one academic year. We will also discuss how this early analysis will guide updates to the survey to allow for broad applications across institutions and groups of TAs.