Assessment is the key to developing an effective program and tracking the progress of each individual student. In turn, the pillar of assessment is collecting accurate, objective data. In this article, the authors discuss the importance of collecting accurate data on student performance in order to be accountable for the instruction and learning of students. Although barriers sometimes impede data collection, they can be overcome through strategies such as (a) planning, (b) matching collection strategies to the setting, (c) recording own behavior, (d) using specific rubrics, (e) collecting data on one or two students a day, (f) training and directing paraeducators, (g) teaching students to self monitor, and (h) utilizing simple equipment to record data. Once accurate and sufficient data is collected, placements, planning, modifications, instruction, and feedback are easier, more valid, and effective. (Contains 3 tables.)