A researcher decides to study the effects of dance therapy on self-esteem in emotionally disturbed adolescents.
A researcher decides to study the effects of dance therapy on self-esteem in emotionally disturbed adolescents. One residential program consents to try the dance therapy treatment, whereas another similar program refuses to try dance therapy, but allows the researcher to measure self-esteem. Self-esteem is measured before and after treatment in both groups. This is an example of a __________ design