The purpose of this extended commentary article is to frame the set of studies in the first of two issues and recommend areas of inquiry for future research. This special series issue features studies examining the technical qualities of formative assessment procedures that were developed to inform intervention. This article intends to emphasize issues in the current set of studies that do not appear central to early numeracy curriculum-based measurement (EN-CBM) research. To the extent possible, we expect that this two-volume series will result in scientific and practical advances. Despite this lofty intention, this series can neither represent all issues important to stakeholders nor characterize the full body of applied and basic research in early numeracy assessment. As such, we focus on a set of theoretical frameworks to guide the current and future development of EN-CBM. [For Part 1, see EJ935764.]