As children grow, they transition from home to school environments, where they acquire and master knowledge and skills, and develop an image of themselves as learners and develop several types of relationships with adults as they grow. As they enter and remain in school, these relationships expand from being solely with parents and caretakers to include their teachers. Due to the large amount of time children spend in school, it is important to examine and understand how the school environment and its affordances, and the relationships that children form while there, influence their lives and, especially, their academic success or failure. This book examines the influence of student-teacher relationships and teacher support on the academic achievement and satisfaction with school for K-5 students. The study used longitudinal growth modeling, specifically, cross-classified random effects modeling, to examine the effect of these relationships on students' performance. The results provide insights on how these relationships affect achievement of specific groups of students.