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 nonprobability 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 
online 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.

Online 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).