Thesis advisor: Penny Hauser-Cram / This dissertation utilized data from the Early Intervention Collaborative Study (EICS), a longitudinal study of children with developmental disabilities (DD) and their families (Hauser-Cram, Warfield, Shonkoff, & Krauss, 2001). The sample for this dissertation consisted of 170 children with DD, their parents, and their teachers. During home visits at ages 2 and 3, mothers and fathers reported on indicators of the home and family environment, and interactions between children and their mothers were observed. At ages 3, 5, 8, 10, and 15, teachers reported on children's levels of classroom-based adaptive functioning. Multilevel modeling was used to examine children's trajectories of classroom-based adaptive functioning. Indicators of the early childhood home and family environment were explored as predictors of these trajectories. The following research questions were addressed: (1) What are the trajectories of classroom-based adaptive functioning among children with DD from ages 3 to 15? (2) Are levels of adaptive functioning in the classroom stable over time, between the ages of 3 and 15? (3) Is there variability in rates of change in adaptive functioning over time, with some children developing more rapidly than others? (4) Do characteristics of the early childhood home and family longitudinally predict children's adaptive functioning in the classroom at age 3 and from ages 3 to15? (5) Which domains of classroom adaptive functioning are predicted by characteristics of the home and family? Results indicated that children's classroom-based adaptive functioning raw scores increase over time. In each domain of adaptive functioning (socialization, communication, and daily living skills) there was significant variability in initial status and rate of change. As hypothesized, quality of early childhood mother-child interaction was predictive of adaptive functioning, with higher quality mother-child interaction associated with more positive functioning. Contrary to hypotheses, the number of negative life events experienced by the family during early childhood was also positively related to classroom adaptive functioning, with more events related to higher levels of functioning. Overall, the findings indicated the influence of the early childhood home and family environment on classroom-based adaptive functioning over time. Policy implications and areas for future research are discussed. / Thesis (PhD) — Boston College, 2015. / Submitted to: Boston College. Lynch School of Education. / Discipline: Counseling, Developmental and Educational Psychology.