Sampling Designs

Non-Probabilistic Sampling Designs: Convenience Sample Voluntary Response Sample Haphazard Sample

Probabilistic Sampling Designs: SRS (Simple Random Sample) Stratified Sample Cluster Sample Systematic Sample In each sampling design, randomization is involved, i.e. every one has an equal chance of being chosen SRS is the only method that ensures that every sample of size n has an equal chance of being chosen.

Period 1: CW Responses VictoR, Hadley Researchers will be able to differentiate between the effect of the treatment from the body’s natural ability to lower its blood pressureas illustrated by the placebo effect. Researchers can see how effective themeds really are.

Period 1: CW Responses Nick, Courtney Drosjack The disadvantage of having volunteers is that if someone with lower blood pressure than another participant might react poorly to the medicine or might not need to be on the medicine as long.

Period 1: CW Responses Courtney Dowell, Rachel Because it was distributed randomly, it could be blind but the experiment did not specify if the researchers knew which volunteers got which treatment, unsure

Period 5: CW Responses Ali & Maggie You would get an unregulated variety of blood pressures, ages, genders, and other health issues.

Period 5: CW Responses Maria & Erika Blind from the patients point of view if they do not know what they are getting.

Period 6: CW Responses Eric and Addy The placebo creates a control group and accounts for the mental effects of taking medication.

Period 6: CW Responses Denver & Mary Only people who admit that they have high blood pressure will join. (cannot generalize results)

Period 6: CW Responses Julian & Nilu Yes, because the volunteers don’t know what they are taking (placebo or meds – pills look the same) or how much. Double Blind: ppl issuing meds don’t know what it is (placebo vs meds)