Pub Date : 2025-12-22DOI: 10.1080/00031305.2025.2606079
James A. Hanley
Although we have had nearly a century to refine it, our teaching of confidence intervals for parameters is still imperfect. Despite all of our warnings regarding these intervals, it is not uncommon for end-users to mis-interpret them. We discuss some possible reasons for this, and using a printed figure and a Shiny app, work through a simple and close-to-home example while trying to avoid many of these traps. We urge teachers to (a) begin with contexts that require less technical knowledge, or where the technical details can be kept out of the way (b) avoid the traditional (and symmetric) ‘point estimate a z- or t-based margin of error’ confidence intervals that lead to lazy and muddled thinking (c) start with a direct approach – rather than an indirect frequentist one that can end up being misinterpreted and (d) encourage the reverse logic that asks what parameter values might have produced the data we see, rather than what data values will be produced by a parameter value.
{"title":"Probabilistic parameter estimates that require less small print","authors":"James A. Hanley","doi":"10.1080/00031305.2025.2606079","DOIUrl":"https://doi.org/10.1080/00031305.2025.2606079","url":null,"abstract":"Although we have had nearly a century to refine it, our teaching of confidence intervals for parameters is still imperfect. Despite all of our warnings regarding these intervals, it is not uncommon for end-users to mis-interpret them. We discuss some possible reasons for this, and using a printed figure and a <span>Shiny</span> app, work through a simple and close-to-home example while trying to avoid many of these traps. We urge teachers to (a) begin with contexts that require less technical knowledge, or where the technical details can be kept out of the way (b) avoid the traditional (and symmetric) ‘point estimate <span><img alt=\"\" data-formula-source='{\"type\":\"image\",\"src\":\"/cms/asset/489dd3c1-6837-4878-ad3f-ec142d578d2d/utas_a_2606079_ilm0001.gif\"}' src=\"//:0\"/></span><span><img alt=\"\" data-formula-source='{\"type\":\"mathjax\"}' src=\"//:0\"/><math display=\"inline\"><mo>±</mo></math></span> a <i>z</i>- or <i>t</i>-based margin of error’ confidence intervals that lead to lazy and muddled thinking (c) start with a direct approach – rather than an indirect frequentist one that can end up being misinterpreted and (d) encourage the reverse logic that asks what parameter values might have produced the data we see, rather than what data values will be produced by a parameter value.","PeriodicalId":50801,"journal":{"name":"American Statistician","volume":"45 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145801429","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-22DOI: 10.1080/00031305.2025.2603256
Nils Lid Hjort, Emil Aas Stoltenberg
The Stirling approximation formula for 𝑛! dates from 1730. Here we give new and instructive proofs of this and related approximation formulae via tools of probability and statistics. There are connections to the Central Limit Theorem and also to approximations of marginal distributions in Bayesian setups, with arguments which can be worked through by Master and PhD level students (and above). Certain formulae emerge by working through particular instances, some independently verifiable but others perhaps not. A particular case yielding new formulae is that of summing independent uniforms, related to the Irwin–Hall distribution. Yet further proofs of the Stirling flow from examining aspects of limiting normality of the sample median of uniforms, and from these again we find a proof for the Wallis product formula for 𝜋. A section detailing historical aspects and development is included, from Wallis 1656 and de Moivre and Stirling 1730 to Laplace 1778, etc.
{"title":"Probability Proofs for Stirling (and More): the Ubiquitous Role of 2π\u0000","authors":"Nils Lid Hjort, Emil Aas Stoltenberg","doi":"10.1080/00031305.2025.2603256","DOIUrl":"https://doi.org/10.1080/00031305.2025.2603256","url":null,"abstract":"The Stirling approximation formula for <span><img alt=\"\" data-formula-source='{\"type\":\"image\",\"src\":\"/cms/asset/65e2d19f-3328-49b9-9cec-082ae3947173/utas_a_2603256_ilm0002.gif\"}' src=\"//:0\"/></span><span><mjx-container aria-label=\"n factorial\" ctxtmenu_counter=\"0\" ctxtmenu_oldtabindex=\"1\" jax=\"CHTML\" overflow=\"linebreak\" role=\"tree\" sre-explorer- style=\"font-size: 121%;\" tabindex=\"0\"><mjx-math aria-hidden=\"true\" data-semantic-structure=\"(2 0 1)\"><mjx-mrow data-semantic-children=\"0,1\" data-semantic-content=\"1\" data-semantic- data-semantic-owns=\"0 1\" data-semantic-role=\"endpunct\" data-semantic-speech=\"n factorial\" data-semantic-type=\"punctuated\"><mjx-mi data-semantic-annotation=\"clearspeak:simple\" data-semantic-font=\"italic\" data-semantic- data-semantic-parent=\"2\" data-semantic-role=\"latinletter\" data-semantic-type=\"identifier\"><mjx-c>𝑛</mjx-c></mjx-mi><mjx-mo data-semantic- data-semantic-operator=\"punctuated\" data-semantic-parent=\"2\" data-semantic-role=\"exclamation\" data-semantic-type=\"punctuation\"><mjx-c>!</mjx-c></mjx-mo></mjx-mrow></mjx-math></mjx-container></span> dates from 1730. Here we give new and instructive proofs of this and related approximation formulae via tools of probability and statistics. There are connections to the Central Limit Theorem and also to approximations of marginal distributions in Bayesian setups, with arguments which can be worked through by Master and PhD level students (and above). Certain formulae emerge by working through particular instances, some independently verifiable but others perhaps not. A particular case yielding new formulae is that of summing independent uniforms, related to the Irwin–Hall distribution. Yet further proofs of the Stirling flow from examining aspects of limiting normality of the sample median of uniforms, and from these again we find a proof for the Wallis product formula for <span><img alt=\"\" data-formula-source='{\"type\":\"image\",\"src\":\"/cms/asset/fdc92f7b-9d1d-4e7e-9789-f159d9b7d2f2/utas_a_2603256_ilm0003.gif\"}' src=\"//:0\"/></span><span><mjx-container aria-label=\"pi\" ctxtmenu_counter=\"1\" ctxtmenu_oldtabindex=\"1\" jax=\"CHTML\" overflow=\"linebreak\" role=\"tree\" sre-explorer- style=\"font-size: 121%;\" tabindex=\"0\"><mjx-math aria-hidden=\"true\" data-semantic-structure=\"0\"><mjx-mi data-semantic-annotation=\"clearspeak:simple\" data-semantic-font=\"italic\" data-semantic- data-semantic-role=\"greekletter\" data-semantic-speech=\"pi\" data-semantic-type=\"identifier\"><mjx-c>𝜋</mjx-c></mjx-mi></mjx-math></mjx-container></span>. A section detailing historical aspects and development is included, from Wallis 1656 and de Moivre and Stirling 1730 to Laplace 1778, etc.","PeriodicalId":50801,"journal":{"name":"American Statistician","volume":"5 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145801448","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}