Statistical Applets

The Reasoning of a Statistical Test

A statistical test assesses the evidence provided by data against some claim (the null hypothesis H0). This applet allows you to gather data until you are ready to reach a conclusion about the truth of a null hypothesis. It illustrates the reasoning of tests: are the data compatible with a claim, or do they give evidence against it?

The basketball team at State University claims that each of their players makes 80% of his free throws. That's a null hypothesis, and is represented by the blue horizontal line on the graph. Have players try shooting free throws and see whether or not you think this null hypothesis can be rejected.

Ask a State University player to shoot free throws by clicking SHOOT. You can get more data by clicking Shoot repeatedly. Do the data appear to agree with the 80% claim or to give evidence against it? When you are satisfied, click "Show true probability" to see the truth for this player. Click NEW SHOOTER to test a different player, who may have a different free throw percent.