Handout 10.6:

Deciding on a Significance Level

Decide on a significance level.

1. p < .05 is standard

2. What would be the advantages of using p < .01 instead of p < .05?

Less likely to make Type 1 error (Less likely to mistake a chance difference between the group means for a treatment effect).

3. What would be the disadvantages of using p < .01 instead of p < .05?

More likely to make a Type 2 error. That is, because you would have less power, you would be more likely to dismiss a real treatment effect as a coincidence.

Back to Chapter 10 Main Menu