In this study, the authors administered two instruments designed to assess and predict teacher effectiveness, the Teacherinsight Interview (TI) and the Renaissance Teacher Work Sample (TWS). The authors asked whether the TWS could serve as a significant predictor of the Tl score. The participants were 396 teacher candidates. This study showed that Praxis Principles of Learning and Teaching scores are significantly correlated with TWS score and TI score. Furthermore, certification level was significantly related to both TI and TWS total scores. However, a stepwise regression revealed only two variables -- certification level and Praxis PLT score -- as significant predictors of TI scores.