Historically, school psychologists have been in public or community service. They tended to work in public school buildings and their practice has focused on individual children. Experts in family intervention use the system property of wholism to plan small changes in family patterns with the hope that any small change will affect the family complaint. The assignment of the task affects not only those who actually perform the task, but has potential effects on the differentiation of each subsystem in the family. Although general systems theory has been extremely influential in family intervention conceptualizations, school psychologists are probably more familiar with Adlerian and behavioral approaches. Strategic family therapy tends to be problem-focused. Most characteristic of structural family therapy is attention to family subsystems, roles, boundaries, and triangles. Triangles are important to structural therapists. Solution-focused therapists adopt a brief therapy model that sees the client's problem as the "patient".