Random Sampling Techniques

The two major types of sampling in quantitative research are random sampling and nonrandom sampling.

Random sampling produces representative samples.

Nonrandom sampling does not produce representative samples.

Simple Random Sampling

The first type of random sampling is called simple random sampling.

It's the most basic type of random sampling.

It’s an equal probability sampling method (which is abbreviated by EPSEM).

Remember that EPSEM means "everyone in the sampling frame has an equal chance of being in the final sample."

Using an EPSEM is important because that is what produces "representative" samples (i.e., samples that represent the populations from which they are selected).

As shown below, simple random sampling is not the only equal probability sampling method (EPSEM).

Sampling experts recommend random sampling "without replacement" rather than random sampling "with replacement" because the former is a little more efficient in producing representative samples (i.e., it requires slightly fewer people and is therefore a little cheaper).

“How do you draw a simple random sample?"

One way is to put all the names from your population onto pieces of paper, put them in a hat, and select a subset (e.g., pull out 100 names from the hat).

In the chapter we demonstrate the use of a table of random numbers.

These days, researchers often use computer programs to randomly select their samples.

Here are two programs that you can use for simple random sampling: http://www.randomizer.org and http://www.random.org