When children come to the attention of the child welfare system, they become involved in a decision-making process in which decisions are made that have a significant effect on their future and well-being. The decision to remove children from their families is particularly complex, yet surprisingly little is understood about this decision-making process. As a result, instrumentation has been developed and adapted over the past 20 years to further understand variations in child welfare outcomes that are decision-based and, in particular concerning the removal decision, in order to provide a more thorough understanding of the intersecting factors that influence caseworker decisions. This chapter presents research and the development and use of this instrument, drawing from the decision-making ecology as the underlying rationale for obtaining the measures. The instrument was based on the development of decision-making scales used in multiple studies and administered to child protection caseworkers in several states. This effort is part of a larger program of research that seeks to better understand decision-making processes in child welfare systems in order to promote fairness, accuracy, and improved outcomes among children and families.