The Personal Responsibility Education Program (PREP), authorized by Congress in 2010, is one of the largest federally funded programs designed to prevent adolescent pregnancy and sexually transmitted infections and prepare youth for successful transition to adulthood. PREP legislation requires grantees to incorporate into their programs content on…

Although basing instruction on learning trajectories (LTs) is often recommended, there is little direct evidence regarding the premise of a LT approach--that instruction should be presented (only) one LT level beyond a child's present level. We evaluated this hypothesis in the domain of early shape composition. One group of preschoolers, who were…

Although basing instruction on learning trajectories (LTs) is often recommended, there is little direct evidence regarding the premise of an LT approach--that instruction should be presented (only) one LT level beyond a child's present level. We evaluated this hypothesis in the domain of early shape composition. One group of preschoolers, who were…