Significance (5% FDR)

A result unlikely to be chance alone, after allowing for how many were tested at once.

Test three hundred pairs at the usual 5% and about fifteen look significant by luck. The false-discovery-rate adjustment raises each p-value to a q-value so that, among everything flagged, at most one in twenty is expected to be a false alarm. Significance says a difference is unlikely to be noise; it says nothing about cause, and nothing about whether the relationship will continue.

Formula

q(k) = min over j ≥ k of p(j) × m ÷ j   (p sorted, m tests)

How to read it

Flagged when q is below 0.05.

In Kereon

Charts · Correlation. Benjamini–Hochberg, within each family on screen: every pair's test of one kind, or every change along one rolling chart. Correlation ≠ 0: Student's t (Pearson, Spearman) or the normal approximation (Kendall). A change, a difference from history or between normal and stressed markets: two independent correlations compared by Fisher's z. Returns cluster in size, so these are approximations.

Also called: significance, q-value, q value.

Related terms

The whole glossary · Investing tools