Many interventions are characterized by repeated observations on the same individuals (e.g., baseline, mid-intervention, two to three post-intervention observations), which offer the opportunity to consider differences in how individuals vary over time. Effective interventions may not be limited to changing means, but instead may also include…

Describes a model of adaptation to the environment across the life span. Proposes that an individual's performance in an activity is affected not only by cognitive capacity but also by perceptions and definitions of the activity. Empirical support for the model, based on a survey of individuals' everyday experiences and on laboratory studies, is…