Sophia Learning
Sophia: Sampling and Prediction: Lesson 1
This lesson demonstrates how sampling can help predict outcomes. It is 1 of 2 in the series titled "Sampling and prediction."
Sophia Learning
Sophia: Sampling & Predictions
This lesson demonstrates how sampling can help predict outcomes.
Rice University
Hyper Stat Online Statistics Textbook: Biased Sample
This site provides a definition for what biased sampling is and gives an example of a situation in which biased sampling may occur.
Web Center for Social Research Methods
Research Methods Knowledge Base: Probability Sampling
This site from Cornell University contains great information on random or probability sampling. Definitely a site worth checking out on the subject.
University of Glasgow
Statistics Glossary: Cluster Sampling
Contains a definition for what cluster sampling is, when it is used, and also provides an example situation for when it would be used.