KNR295Sampling

Slide 1

Sampling & External Validity

Chapter 2

KNR 295:Sampling

Slide 2External Validity: Critiquing

The sampling model…

KNR 295:Sampling

Slide 3External Validity: Critiquing

The sampling model… Goal (claim) is representative

sampling Often not attainable -

Who to generalize to? Availability of the true “representative” sample? Will the sample be representative of other

times?

An alternative is to model (or critique) the differences in a systematic way…

KNR 295:Sampling

Slide 4External Validity: Critiquing

Proximal similarity model (Campbell, 1963)

KNR 295:Sampling

Slide 5External Validity: Critiquing

Proximal similarity model (Campbell, 1963) The idea here is to quantify the

difference between the various properties of the study you are considering, and that to which you want to generalize, and then consider the likelihood that this difference would alter the research’s findings

KNR 295:Sampling

Slide 6External Validity: Critiquing

What to do? Evaluate, critique, consider… And if that fails, replicate

KNR 295:Sampling

Slide 7Sampling Terminology