The Child Behavior Checklist originated in 1991 by Dr. Thomas Achenbach. The questionnaire is completed by a parent, teacher or other individual who knows the child well. Achenbach's checklist revolutionized the field of child and adolescent psychopathology by offering an alternative way of approaching and understanding behavioral problems. Expanding the field from just two categories of childhood disorders, Achenbach's system helps adults understand a variety of childhood behavior problems.