A psychologist whose specialty is concerned with the science and practice of psychology with children, youth, families; learners of all ages; and the schooling process. The basic education and training of school psychologists prepares them to provide a range of psychological diagnosis, assessment, intervention, prevention, health promotion, and program development and evaluation services with a special focus on the developmental processes of children and youth within the context of schools, families and other systems. School psychologists are prepared to intervene at the individual and system level, and develop, implement, and evaluate preventive programs. In these efforts, they conduct ecologically valid assessments and intervene to promote positive learning environments within which children and youth from diverse backgrounds to ensure that all have equal access to effective educational and psychological services that promote healthy development