Misleading description

Statistically significant

Look out for results that are reported as “statistically significant” or “not statistically significant”. Don’t confuse “statistical significance” with “importance”.

“Statistical significance” is often confused with “importance”. The cut-off for considering a result as statistically significant is arbitrary, and statistically non-significant results can be either informative (showing that it is very unlikely that a treatment has an important effect) or inconclusive (showing that the relative effects of the interventions compared are uncertain).

However, statistical significance does not tell us anything about how important an effect is. A small, unimportant effect can be “statistically significant”. Similarly, a large, important effect can be “statistically non-significant”.

REMEMBER: Claims that results were significant or non-significant usually mean that they were statistically significant or statistically non-significant. This is not the same as important or not important. Do not be misled by such claims.