Currently, states are examining early childhood for its potential benefits to K12 and postsecondary education. However, these benefits are difficult to assess because of incomplete early childhood data in statewide longitudinal data systems (SLDSs). The need for data can pressure state education agencies (SEAs) to quickly increase the collection of--and access to--early childhood data. However, in order to successfully facilitate the use of these data, SLDS staff must proceed thoughtfully. Careful planning of data use will anchor the P-20W system with concrete and tangible needs that are actionable. In effect, the agency will ensure that appropriate, relevant data are made available to their primary users, who will then be better able to inform key early childhood decisions. This document examines the planning phase of the Early Childhood Data Use Framework through the experiences of Arkansas's and Washington State's SLDS P-20W agencies. (author abstract)