1. Section 1.3
Data Collection and Experimental Design

2. Data Collection Methods
1. Observational study
2. Experiment
3. Simulation
4. Survey

3. EX: which method of data collection would you use? Why?
14. A study of the effect of a product’s warning label to determine whether consumers will still buy the product.
16. A study of how often people wash their hands in public restrooms.

4. Sampling Techniques
Census: a count or measure of the entire population. SAMPLES are part of the population.
Random Sample: every member of the population has an equal chance of being selected.
Stratified Sample: the population is divided into subsets (strata), then a sample is randomly selected from each of the strata.

5. More Sampling Techniques
Cluster Sample: population is divided into groups (clusters), then select all members in one or more clusters.
Systematic Sample: Each member of the population is assigned a number, placed in order, then select every nth member starting at a randomly selected number.
Convenience Sample: uses only available members of the population.

6. EX: What sampling technique was used?
20. Chosen at random, 500 rural and 500 urban persons age 65 and older are asked about their health and their experience with prescription drugs.
26. From calls made with randomly generated telephone numbers, 1012 respondents are asked if they rent of own their residences.