A subset, or part, of the population.
A researcher observes and measures characteristics of interest of part of a population.
Every member of the population has an equal chance of being selected.
Divide a population into groups (strata) and select a random sample from each group.
Consist of information coming from observations, counts, measurements, or responses.
Choose only members of the population that are easy to get. (No recommended. Often leads to biased studies.)
Choose a starting value at random. Then choose every 00th number of the population.
Occurs when an experiment cannot tell the difference between the effects of different factors on a variable.
Numerical measurements or counts.
Divide subjects with similar characteristics into blocks, and then within each block, randomly assign subject to treatment groups.
A numerical description of a population characteristic.
Involves organizing, summarizing, and displaying data. E.G. Tables, charts, averages.
Count or measure of part of a population and is more commonly used in statistical studies
The collection of ALL outcomes, responses, measurements, or counts that are of interest.
A Technique where the subject does not know whether he or she is receiving a treatment or a placebo.