• Terminology
• Sampling
• Selecting a Sample
• Comments on Sampling
• Ex:  Voluntary Response
• Probability Sampling Design
• Probability Sampling Design
• Simple Random Sample (SRS)
• SRS of size n
• Stratified Random Sample
• Ex:  Stratified Random Sampling
• Comment on Stratified Sampling
• Samples can suffer from Bias:
• Completely Randomized Design – experimental units are assigned randomly among all the treatments
• Randomized Block Design – experimental units are assigned randomly among all the treatments within each block
• Slide 17
• Slide 18