BACKGROUND	The purpose of this randomized trial is to compare the effectiveness , cost , and social validity of two manualized evidence-based PT programs that were developed and tested on different populations and employ different delivery models : ( 1 ) The Chicago Parent Program ( CPP ) , a group-based program developed in collaboration with a community advisory board of African-American and Latino parents ; and ( 2 ) Parent-Child Interaction Therapy ( PCIT ) , an individualized parent-child coaching model considered to be ` the gold standard ' for parents of children with externalizing behavior problems .\