Sampling and sources of bias

sampling methods

a few sources of sampling bias

\"convenience sample\" : individuals who are easily accessible are more likely to be included in the sample.\"Non-response\" : if only a (non-random) fraction of the randomly sampled people respond to a survey such that the sample is no longer representative of the pupulation\"voluntary response\" : occurs when the sample consists of people who volunteer to respond because they have strong opinion on the issue.

simple random sample (SRS)

cluster sample

inference

multistage sample

stratified sample

exploratory analysis

representative sample