This applet presents a slightly different representation of power analysis
than in Figure 8.4. For purposes of resolution, the numbers in the example have
been multiplied by 10. When the applet loads, it displays the Power (= 1 - beta)
for the example in the text. Use the slider to increase the number of observations
until the power is greater than the desired .95 (so that beta will be less than
.05) as illustrated in the textbook. At any point, you may click on your browser's
Refresh or Reload button to restore the applet to the original display. Investigate
how changing the assumed standard deviation (left slider) or the magnitude of
the difference to be detected (right slider) would affect statistical power.
Note: The values in this applet are for one-tailed tests at alpha = 0.05 or
two-tailed tests at alpha = 0.10
All applets and text are © 2008, Duxbury Press, and may not be copied, altered, decompiled, or distributed in any manner without the explicit written permission of the author and publisher.