# Alpha correction in a family of tests

Suppose that one runs 8 correlation analyses but in two separate batches: Would the alpha-correction apply to all 8 tests as a family or each of the 4 tests as a family?

For example, if there are two research questions and both require correlation analysis, the researcher conducts the first 4 tests (for research question 1) and then conducts the second 4 tests (for research question 2). In this case, should the alpha be corrected for a family of 4 tests or for a family of 8 tests? (Note that the same statistical test--Pearson's $r$--is used in both cases.)

I understand there isn't a consensus on this matter (as with many other matters in statistics as I am learning fast!) but some broad guidelines would be most helpful.

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 There was similar question on what might be considered a family of tests. – ttnphns Jan 11 '12 at 11:27 Thanks! The context above is slightly different, I believe, though. As always, many thanks for the responses. – Adhesh Josh Jan 11 '12 at 22:30 @AdheshJosh: I think you have to click some symbol (I don't remember what) to award the bounty to MånsT. – pul Jan 16 '12 at 13:12 I did click "+50" but nothing happened! – Adhesh Josh Jan 17 '12 at 6:01