Probability Sampling Tutorial

Saavy statisticians use probability samples when they conduct survey research. Probability sampling makes it possible for researchers to estimate the extent to which sample estimates reflect true population parameters.

About the Tutorial

This tutorial covers the essence of probabilty sampling clearly and simply in just a few short lessons. The tutorial focuses on four main topics:

  • Prerequisites. To use probability sampling effectively, it helps to know about non-probability samples and survey bias.
  • Data collection. We look at three methods for collecting probability samples: simple random sampling, stratified sampling, and cluster sampling.
  • Analysis. It is not enough to collect data in the right way. You also need to know how to analyze it correctly.
  • Sample planning. How to compare different data collection methods to find the optimum design (most precision, least cost).

This tutorial is designed for students and researchers who have some familiarity with introductory statistics (e.g., a high school statistics course or Advanced Placement Statistics).

How to Use This Tutorial

Individual lessons are accessible through the table of contents, which can be found in the vertical column on the left side of the page. You should work through lessons in the order in which they appear; because some lessons build on previous lessons.

Individual lessons are accessible through the table of contents, which can be accessed by tapping the "Probability Sampling" button at the top of the page. You should work through lessons in the order in which they appear; because some lessons build on previous lessons.

Additional Helpful Resources

As you progress through the tutorial, take advantage of the following helpful resources.

  • Analytical tools. Stat Trek provides a variety of analytical tools - on-line statistical tables and probability calulators - to take the drudgery out of statistical computations. The tutorial will alert you to these tools, all of which are free.
  • Sample problems. Most of the lessons include sample problems. The sample problems test your knowledge. They also illustrate shortcuts and solutions to common statistics problems.
  • On-line help. Stat Trek's online Statistics Dictionary takes the mystery out of statistical jargon. If any term or concept is unclear, visit the dictionary for additional explanation.

Note: The dictionary can be accessed by clicking the Help tab in the main menu (located at the top of this web page).