Statistical significance
An assessment of how far an observed result departs from what chance alone produces over the same number of observations.
How to read the number
The question is put the other way round from the intuitive one: not whether the data supports a rule, but how often the same result appears where no rule exists at all.
When the metric lies
Trying dozens of variants all but guarantees a finding that looks significant. The count of hypotheses tested must enter the calculation, or significance measures the diligence of the search.
Also known as: statistical significance