System reform in U.S. heartland is the story of a decade-long effort to change the ways we think about children and youth who experience learning or behavior problems in educational settings. This fundamentally different way of thinking involves a shift from seeking the causes and solutions to learning and emotional/behavioral problems in inferred internal states of the individual, to an examination of behavioral discrepancies from typical or expected patterns of behavior. These discrepancies are resolved through changes in social and instructional environment, based on the application of principles of instructional design and behavior change. The social learning or behavior model used in Iowa is described. Assessment has been a salient activity in the roles of Iowa school psychologists; however, vast changes have occurred in assessment purposes, techniques, and outcomes. Purposes focus more on interventions, and techniques increasingly involve the use of direct and frequent measures of behaviors to gather information in natural environments. The most important goal in Iowa system reform is the improved application of the available knowledge on assessment, instruction, learning, and behavior change. Reductions in the amount of time devoted to standardized testing for eligibility determination has provided expanded opportunities for school psychologists to be involved in new roles. Contains 33 references. (JBJ)