https://mdahsanul.netlify.app/tags/p-value/ Recent content in P-Value on Md Ahsanul Islam Hugo en-us Sun, 11 Oct 2026 00:00:00 +0000 https://mdahsanul.netlify.app/post/significant-vs-not-significant/ Sun, 11 Oct 2026 00:00:00 +0000 https://mdahsanul.netlify.app/post/significant-vs-not-significant/ <p>A training program improves test scores for men (<code>\(p = 0.009\)</code>) but not for women (<code>\(p = 0.23\)</code>). A drug lowers blood pressure in one trial and “fails” in another. In a regression, TV advertising predicts sales but radio advertising does not. Each of these sentences invites the same conclusion, which is, the two things behave differently.</p> <p>That conclusion does not follow. It is one of the most common errors in applied statistics, and Gelman and Stern (<a href="#ref-gelman2006">2006</a>) gave it a memorable name in <em>The American Statistician</em>: <strong>the difference between “significant” and “not significant” is not itself statistically significant</strong>. A free copy of the paper is on <a href="https://sites.stat.columbia.edu/gelman/research/published/signif4.pdf">Andrew Gelman’s website</a>.</p>