Interim assessments have been defined variously in different contexts and can be used for predictive purposes or instructional purposes. In this paper, we present results from a study where we evaluated reporting needs for interim assessments designed for instructional purposes and intended to be used at the end of defined curriculum units. Results from such unit assessments should help teachers determine gaps in student understanding and inform ongoing instructional decision-making. Our goal was to determine if learning progressions (LPs) could serve as the cognitive lens through which teachers can evaluate how their students' understanding of key constructs improves through periodic unit assessments. Therefore, we used the LP framework in mathematics and the key practices (KP) framework for English language arts (ELA) to design preliminary teacher report mock-ups for these unit assessments. Within a utilization-oriented evaluation framework, we conducted six needs-assessment focus groups with elementary and middle school mathematics (n=12) and ELA (n=11) teachers to specifically evaluate the extent to which they find results presented within the LP and KP frameworks understandable and useful for their instructional practice. Results from the focus groups show teachers' overall needs for types of information sought from unit assessment reports, the extent to which teachers are familiar with the LP and KP frameworks, their interpretations (including confusions) of the information presented in the preliminary mock-ups, and their additional needs for reports from unit assessments to be instructionally useful.