# Sample size for Pearson correlation and the reverse coded items for correlation analysis?

Participants (N=14) filled in two questionnaires at two points of time, and I want to see the correlation between the variables.

Is this sample size sufficient?

Also, should I have reverse coded the items before running the correlation analysis?

-
Are you interested in the correlation between each variables/items or a composite score (e.g., sum or mean score) derived from them? – chl Oct 16 '12 at 21:46
I'm looking at the correlation between each item. – Julie Oct 16 '12 at 21:52
"Is this sample size sufficient?" ... sufficient to do what, exactly? You can compute correlations with fewer data points. And why would you reverse-code anything? – Glen_b Oct 16 '12 at 21:54
Then reverse scoring doesn't matter, but we'll probably want to know how many items you have. – chl Oct 16 '12 at 21:54
I meant is the sample size sufficient for correlation analysis? – Julie Oct 16 '12 at 21:59
show 1 more comment

$SE(r) = \frac{(1-\rho^2)}{\sqrt{n-1}}$