A study of the effects of two years of teacher training in the Learning Experiences and Alternative Program for Preschoolers and Their Parents (LEAP) program on children's improvements in measures of cognitive, language, social, and problem behavior, and autism symptoms, with an analysis of the relationship between child outcomes and fidelity of implementation, teacher characteristics, and child performance at the beginning of the intervention, based on data from 294 preschool children in 56 inclusive classrooms