ABSTRACT
Problem:Researcherswouldliketoexaminetheextenttowhichcigarette advertisingcausesadolescentstosmoke.Forethicalandlegalreasons,atrue experimentinwhicharandomhalfofasampleofadolescentsisexposedto cigaretteadvertisingbytheresearcherscannotbeconducted.Instead,theyrelyon descriptivedataontherelationshipbetweenadvertisingandsmoking.The descriptivenatureofthedatameansthatanyinterpretationsregardingcausality mustbetentative.
