Click on the following links. Please note these will open in a new window.

Video Clips

Hypothesis Testing
This video describes the four steps of hypothesis testing (2:08).

Power and Sample Size
Describes the basic concepts of power and sample size calculations (4:53).

Cohen’s d Effect Size
This is a tutorial on how to calculate Cohen’s d or the effect size for groups with different means (4:49).

Type I and II Errors and the Power of the Test
This video discusses Type I errors, Type II errors, their probabilities of occurring (alpha and beta) and the power of a hypothesis test (8:10).

Audio Clips

Null Hypothesis Testing
This lecture discusses null hypothesis testing, Type I error, Type II error, and p values (27:59).

Bell Curve and Null Hypothesis Testing
This lecture provides an illustrative example of null hypothesis testing and how assumptions regarding the characteristics of the normal curve allow us to make inferences from a sample to the population (26:48).

Power and Effect Size
Lecture discusses power, ways to increase power, and advantages and disadvantages of each method. Also discusses effect size, Type II errors, beta, and power (43:16).

Prison Psychology and the Stanford Prison Experiment
During this NPR clip, Philip Zimbardo discusses his famous psychology experiment and how it relates to current events. This can be applied to learning about hypothesis testing and samples within a population (10:59).

Web Resources

Factors that Affect the Power of a Statistical Procedure
This website includes definitions and simple explanations about the factors that affect power within a sample. Also contains links to other helpful websites related to this topic.

Interpreting Cohen’s d Effect Size
Provides an interactive visualization of Cohen’s d.

Effect Size Calculator
Includes effect size calculators.

The Null Hypothesis: Directional and Nondirectional Tests
This website includes an overview of the null hypothesis and directional versus nondirectional tests.

Hypothesis Test: Difference Between Proportions
This website describes hypothesis testing, provides two sample problems, and discusses the use of the z score.