05.03.2013 Views

Looking Elsewhere and Looking Everywhere (a.k.a. Multiple Testing ...

Looking Elsewhere and Looking Everywhere (a.k.a. Multiple Testing ...

Looking Elsewhere and Looking Everywhere (a.k.a. Multiple Testing ...

SHOW MORE
SHOW LESS

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

Holm-Bonferroni Method<br />

Advantage: Works for any (discrete domain) setup!<br />

Disadvantage: Too conservative when T large<br />

Holm’s modification increases average # of hypotheses rejected at level α<br />

(but does not increase power for overall rejection of H0)<br />

Holm’s Procedure<br />

1 Suppose we reject H0,t for large values of a test statistic Wt<br />

2 Order individual test statistics, largest to smallest: W (T ) ≥ . . . ≥ W (1)<br />

3 Starting from t = T <strong>and</strong> going down, reject all H 0,(t) such that W (t)<br />

supercritical at level α/t. Stop rejecting at first subcritical W (t).<br />

Genuine improvement over Bonferroni if want to detect as many signals as<br />

possible, not just existence of some signal<br />

Both Holm <strong>and</strong> Bonferroni reject the global H0 if <strong>and</strong> only if sup t Wt<br />

supercritical at level α/T wrt distribution of corresponding W under H0<br />

Victor M. Panaretos (EPFL) Progress on Statistical Issues in Searches SLAC – June 2012 8 / 25

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!