Sampling Methods

To find out about a population of interest it is common practice to take a sample.

A sample is generally a lot smaller than the population of interest.

All sampling methods cost about the same, so we should choose our method depending on what will give the best results.

It is more important to get a large sample than to make sure that each item is equally likely to be chosen.

Sampling error is unavoidable if you take a sample.

If you take a larger sample, this increases the sampling error.

Simple random sampling is quite difficult to administer.

A researcher asked every person wearing red who walked past the booth. What kind of sample is this?

A researcher uses a random number generator to look up people on the electoral roll. What kind of sample is this?

Simple random sampling is the easiest method of sampling, but it doesn't give a very good sample.