Transparency Tool for Understanding the Hypothesis Testing Model

Download this pdf document. Its a single page and has two normal distributions on it.

Print it and then have it photocopied onto a transparency.

Cut it horizontally so you have the two distributions.

Now you can create examples and overlay the the transparent distributions on the problem. You can draw in the location of the decision rule, region for Type I errors, regioni for Type II, errors, etc.

For example, draw the axes (green) and position the result of one statistical test (red "poker chip).

Now, overlay the two transparent distributions. Using an eraserable marker, indicate which distribution is the "Ho true", indicate the decision rule, etc.

If you reject Ho, remove the "Ho true" distribution. Shade the decision error and coreect dection regions for the "Ho false" distribution.

Work with a colleague and devise problems for one another.

© 2004 by Burrton Woodruff. All rights reserved. Modified 2/16/04