What Statistical Significance Means

Why We Don’t Really Know What “Statistical Significance” Means: Implications for Educators*

Why We Don’t Really Know What "Statistical Significance" Means: A Major Educational Failure

Significance and importance: some common misapprehensions about statistics.

There are many common misapprehensions about statistics that occur in the literature. We are sure that the three misapprehensions we deal with in this short review are widespread. They concern: 1)what P values mean;2)what an insignificant result means, and what it does not mean; the question of the 'power' of a statistical test;3)the difference between importance and statistical significance.We...

Statistical and clinical significance, and how to use confidence intervals to help interpret both.

Statistical significance is a statement about the likelihood of findings being due to chance. Classical significance testing, with its reliance on p values, can only provide a dichotomous result - statistically significant, or not. Limiting interpretation of research results to p values means that researchers may either overestimate or underestimate the meaning of their results. Very often the ...

Statistical Significance Versus Clinical Importance of Observed Effect Sizes: What Do P Values and Confidence Intervals Really Represent?

Effect size measures are used to quantify treatment effects or associations between variables. Such measures, of which >70 have been described in the literature, include unstandardized and standardized differences in means, risk differences, risk ratios, odds ratios, or correlations. While null hypothesis significance testing is the predominant approach to statistical inference on effect sizes,...