Chapter 4
Topics
1. Research Strategies
 Sample Surveys
 Randomized Experiments
 Observational Studies
 Meta Analysis (ch 25)
2. Terminology
 Population: The big group to whom you want to research. E.g. all PSU
undergraduates, all residents of PA.
 Sample: a subgroup of that population
 Sampling Frame: the group from which the sample is take, preferably this is the
population
 Sample proportion: the number in the group of interest divided by the total
number in the sample.
E.g. from a sample of 1000 PSU students, 400 say that JoePa
should retire.
The sample proportion would be 0.40 or 40%.
 Census: a measurement done on the entire population
3. Probabilitybased sampling methods
 Simple random sample: a sample is randomly drawn from the
population/sampling frame.
Each subject in the population has a equal chance of being
selected.
 Stratified random sampling: the population/sampling frame is partitioned into
some strata or specific groups based on some criteria.
E.g. if sampling from all PSU
undergraduates we could divide this population into strata such as Freshmen,
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
This is the end of the preview.
Sign up
to
access the rest of the document.
 Spring '08
 SEIFRIEDTHOMASJ
 Simple random sample, representative, PSU students

Click to edit the document details