Two well-accepted ideas among educators are (a) performance assessment is an effective means of assessing higher-order thinking skills and (b) data-driven instruction planning is a valuable tool for optimizing student learning. This article describes a locally developed performance task (LDPT) designed to measure critical thinking, problem solving, and written communication skills of elementary and middle school students in a large school district. An investigation was conducted to determine how middle school teachers use LDPT responses to inform instruction and to ascertain how students are reflecting on their performance. Results from an analysis of documents indicated teachers were engaged in formal data-informed practices within professional learning communities. Moreover, educators examined student work samples and planned instruction based on student-specific needs. Strategies to reinforce proficiency in the skills assessed by the district's LDPT are reported.