This study explored principals' reactions to findings from a survey regarding their teachers' evaluation beliefs. As participants in a longitudinal study, these principals were invited to focus group meetings to discuss the teacher survey data, which were sent to them for review prior to the meetings. They were asked to consider data that were puzzling, surprising, inconsistent, or consistent with their perceptions of conducting teacher evaluation. The focus group data were analyzed using the Johari Window, consisting of four domains of awareness. Based on the Johari Window analysis, principals shared teachers' awareness of a checklist approach to observations but maintained different beliefs about a checklist's intentions and efficiencies. Principals were unaware of or disagreed with the following teacher beliefs: (a) principal feedback is marginally effective for teachers' instructional improvement, (b) the evaluation ratings are applied unfairly, and (c) too much of principals' time is allotted to the evaluation process. This study illustrates that principals and teachers have contradictory beliefs regarding the practice and value of teacher evaluation. The researchers suggest that principals should consider applying the Johari Window construct to reveal and explore teacher perceptions that could hinder an effective supervision and evaluation process.