In 2012, the Office of Planning, Research, and Evaluation at the Administration for Children and Families (ACF) engaged Mathematica Policy Research and its partners to conduct a project titled "Assessing Early Childhood Teachers' Use of Child Progress Monitoring to Individualize Teaching Practices." The purpose of the project was twofold: (1) to develop a research-informed conceptual model for early childhood teachers' use of ongoing assessment to individualize instruction, and (2) to create a measure to examine this process. Prior reports describe in detail the results of a literature review, conceptual framework, and measurement plan (Akers et al. 2014; Atkins-Burnett et al. 2014). This report describes the iterative development of the Examining Data Informing Teaching (EDIT) measure. This report includes the results of a pretest study in 18 classrooms and a proposal for next steps for the EDIT. (author abstract)