Objective measurement of the independent variable: a neglected methodological aspect in community-based behavioral research.
D000293:Adolescent; D000367:Age Factors; D001521:Behavior Therapy; D002648:Child; D002653:Child Behavior Disorders / Q000628:therapy*; D003156:Community Mental Health Services; D006801:Humans; D011615:Psychotherapy, Group; D012107:Research Design; D012647:Self-Assessment; D012949:Social Work, Psychiatric