Other's OnLine Resources (Chapter 9)
Small rs Can Be Significant 
 Description:
This interactive online resource allows you to quickly determine the smallest r
that will ne statistically significant for any given sample size. All you do is enter
the value of n; you will then be given the critical values for the .05, .01, and
.001 levels of significance.
 What to Do:
 Click on the colored title of this online resource: "Small rs Can
Be Significant."
 Enter, in the "Sample size (n)" box, the number 10.
 Click on the gray bar that says "Minimum coefficient."
 After a few seconds, the critical values (for alphas of .05, .01, and
.001) will appear as "Results" beneath the gray bar you just clicked. Each
critical value will be referred to as the "minimum r significant at p=alpha."
Try to memorize the size of r that would have p = .05.
 Change the value of the sample size from 10 to 25, and then click the
"minimum coefficient" bar. Compare this critical value with the one you saw
when the sample size was 10.
 The comparison you made of the results in Steps 4 and 5 should show you that
there's an inverse relationship, at any given alpha level, between the critical
value of r and the sample size. If n is large enough, even a small
r will turn out to be statistically significant.
 Sky Huck's Puzzle Question:
Can you show that an r of 0.012 would be significant at the .05 level of
significance if n is large enough?

Comparing 2 Correlations 
 Description:
This interactive resource allows you to see if there is a statistically
significant difference between two correlation coefficients. By
exerting control over (1) the size of the difference between the
two rs and (2) the sample sizes, you'll be able to see that large
sample sizes can turn a small difference into something "significant."
 What to Do:
 Click on the colored title of this online resource: "Comparing
2 Correlations."
 Make 2 private decisions: (a) your level of significance
and (b) whether you want to do a onetailed test or a twotailed
test.
 Enter .50 and .55 as the r values for Samples A and B.
 Enter 100 for each sample size.
 Click "Calculate" and then look to see if you have a statistically
significant finding; this will be the case if the computed
p is smaller that the alpha level you selected in Step #2.
 If you don't have a significant finding, repeat Steps #4
and #5 again and again (each time increasing each n by 100)
until you finally can cross over into "The Wonderful Land
of Significance."
 Sky Huck's Puzzle Question:
What do you think will happen to the computed value of p if you
(1) set each n equal to 100, (2) make the two values of r different
by .20, and (3) change the "location" of your two r values on
the "correlation continuum" (that extends from 1.00 to +1.00)?

