Question: A researcher is interested in discovering if a prison treatment program for substance abuse has any impact on recidivism. A total of 200 men were selected and randomly assigned to treatment or non-treatment conditions. Half the men underwent treatment and the other half did not. After their release, the men were checked to find out if they were reincarcerated within a three year period

Incarceration

Yes No

Treatment program 30 70

No treatment 62 38