Drawing from a three-year qualitative multi-case study that examined three urban elementary schools as these schools instituted grade-level data-based collaboration as a school-wide literacy reform strategy, this article investigates how knowledge of student learning and instructional considerations evolved over time across this collection of grade-level teams from data-based collaboration. For grade-level teams in this study, the generation of student learning knowledge from data-based collaboration was not an automatic outcome, but one that developed over time. The activation and use of student learning knowledge for instructional considerations also developed over time but varied by type of instructional consideration. Principal communication associated with data-based collaboration, a facet of their role as reform sensegivers, is also explored as a factor of influence related to the generation of student learning knowledge and activation and use of knowledge for instructional considerations from data-based collaboration. Of importance, the content of principal communication evolved over time for all three principals and appeared to shape the design and introduction of proximal tools and processes that supported grade-level data-based collaboration that in turn influenced the ways in which student learning knowledge and instructional considerations developed from data-based practices over time. Implications for policy and practice are considered. (Contains 3 notes.)