Other's On-Line Resources (Chapter 12)


Multiple Comparisons
  • Description:
    Although this on-line resource is only text-based (and not interactive), it's packed with interesting information about planned and post hoc tests. For example, it contains a chart that shows clearly why an inflated Type I error occurs, it presents lots of examples from applied studies, and it offers tips for interpreting the p-levels you'll see in research reports.

  • What to Do:
    1. Click on the colored title of this on-line resource: "Multiple Comparisons."
    2. Read the material on the screen that pops up.
    3. Carefully consider the chart that shows how the probability of making a Type I error increases dramatically (over the nominal alpha level) as the number of tests being conducted increases.

  • Sky Huck's Puzzle Question:
    Which researcher (A or B) would be more likely to commit a Type I error? Researcher A uses the hypothesis testing procedure just once to test a null hypothesis that's true (although she doesn't know that), and she sets alpha equal to .20 when making this test. Researcher B uses the hypothesis test procedure 6 times to evaluate a half dozen independent null hypotheses that are all true (although he doesn't know that), and he sets alpha equal to .05 when making each of these 6 tests.

Copyright © 2012

Schuyler W. Huck
All rights reserved.

| Book Info | Author Info |

Site URL: www.readingstats.com

Top | Site Map
Site Design: John W. Taylor V