There are many types of sampling methods because different research questions and study designs require different approaches to ensure representative and unbiased samples.

Practice identifying which sampling method was used in statistical studies, and why it might make sense to use one sampling method over another.

Learn how to conduct significance tests and calculate p-values to see how likely a sample result is to occur by random chance. You'll also see how we use p-values to make conclusions about …

Learn statistics and probability—everything you'd want to know about descriptive and inferential statistics.

Learn how to form questions and gather data to explore those questions. You'll also learn about some investigative techniques, including sampling, survey methods, observational studies, …

If I take a sample, I don't always get the same results. However, sampling distributions—ways to show every possible result if you're taking a sample—help us to identify the different results …

Practice identifying which sampling method was used in statistical studies, and why it might make sense to use one sampling method over another.

Statistics is all about forming questions and gathering data to explore those questions. This unit connects these questions to aspects of research design, including sampling and survey …

In the case of nonresponse bias, a particular group is left out of the survey, so their answers aren't represented in the results. In addition to nonresponse bias, another type of response bias is …

Distinguish between population distributions, sample data distributions, and sampling distributions. Use sample statistics to make inferences about population parameters based on …