Statistical Practice

[NOTE: This is a repost of a blog that Prasanna Parasurama published at the blogsite Towards Data Science]. Prasanna1 “The confidence intervals of the two groups overlap, hence the difference is not statistically significant” The statement above is wrong. Overlapping confidence intervals/error bars say nothing about statistical significance. Yet, a lot of people make the mistake of inferring lack of statistical significance.

[Note: This blog is based on our articles “Blinding Us to the Obvious? The Effect of Statistical Training on the Evaluation of Evidence” (Management Science, 2016) and “Statistical Significance and the Dichotomization of Evidence” (Journal of the American Statistical Association, 2017).] Introduction The null hypothesis significance testing (NHST) paradigm is the dominant statistical paradigm in the biomedical and social sciences.