This article compares regression modeling and propensity score analysis as different types of statistical techniques used in addressing selection bias when estimating the impact of two-year versus one-year Head Start on children's school readiness. The analyses were based on the national Head Start secondary dataset. After controlling for…

Children's social skills are an important class of learned behaviors that facilitate success in the classroom; the primary method used in the assessment of social skills involves having parents or teachers complete standardized checklists using judgments of frequency or intensity. Children's (N = 1,102) social skills were modeled as time-varying…