Thursday, December 11, 2008

Reporting Significance Levels

John asked,

When reporting significance level at the .05 level, if my value is .051 can I report as p = .051 (using three decimal places to show approximation)?

1 comment:

Mari said...

You need not use three decimal places, Just report that p value as p = .05. That is, p = .05 is not p < .05, so you aren't claiming something as significant, but rather letting your reader know the actual significance level.

I have seen people report p = .047, for instance, and I can see pros and cons of that versus p = .05 in that situation, but in general, APA's recommendation is that you report p values to two decimals (with a few exceptions that become relevant next quarter).