{"id":772,"date":"2025-12-23T10:11:59","date_gmt":"2025-12-23T10:11:59","guid":{"rendered":"https:\/\/alandix.com\/statistics\/?page_id=772"},"modified":"2025-12-23T10:15:49","modified_gmt":"2025-12-23T10:15:49","slug":"chapter-8","status":"publish","type":"page","link":"https:\/\/alandix.com\/statistics\/book\/toc\/chapter-8\/","title":{"rendered":"Chapter 8: Common issues"},"content":{"rendered":"<div class=\"embedurl\" data-url=\"https:\/\/alandix.com\/books\/hcistats\/content1e\/chaps\/chap-8.html\" ><!--  Chapter 8 Common issues   -->\n\n<script>\nvar chapnos = 8;\nvar json_url = \"https:\\\/\\\/alandix.com\\\/books\\\/hcistats\\\/content1e\\\/chaps\\\/chap-8.json\";\n<\/script>\n\n\n\n\n\n\n<h3> Contents <\/h3>\n<div class=\"toc\">\n<dl>\n<dt>8.1&nbsp;&nbsp;Cherry picking <\/dt><dd><dl>\n<dt>8.1.1&nbsp;&nbsp;Multiple tests <\/dt>\n<dt>8.1.2&nbsp;&nbsp;Multiple statistics <\/dt>\n<dt>8.1.3&nbsp;&nbsp;Outliers <\/dt>\n<dt>8.1.4&nbsp;&nbsp;Post-hoc hypothesis <\/dt>\n<dt>8.1.5&nbsp;&nbsp;The file drawer effect <\/dt>\n<\/dl><\/dd>\n<dt>8.2&nbsp;&nbsp;Inter-related factors <\/dt><dd><dl>\n<dt>8.2.1&nbsp;&nbsp;Non-independently controllable factors <\/dt>\n<dt>8.2.2&nbsp;&nbsp;Correlated features <\/dt>\n<\/dl><\/dd>\n<dt>8.3&nbsp;&nbsp;Everything is random <\/dt>\n<dt>8.4&nbsp;&nbsp;The same or worse <\/dt><dd><dl>\n<dt>8.4.1&nbsp;&nbsp;Everything is unlikely <\/dt>\n<dt>8.4.2&nbsp;&nbsp;Numeric data <\/dt>\n<dt>8.4.3&nbsp;&nbsp;More complex &lsquo;or worse&rsquo; <\/dt>\n<dt>8.4.4&nbsp;&nbsp;Post-hoc corrections <\/dt>\n<\/dl><\/dd>\n<dt>8.5&nbsp;&nbsp;Simulation and empirical methods <\/dt>\n<dt>8.6&nbsp;&nbsp;What you can say&mdash;phenomena and statisticians <\/dt>\n<\/dl><\/div>\n\n\n<h3> Glossary items referenced in this chapter <\/h3>\n<div class=\"toc\">\n<a href=\"https:\/\/alandix.com\/glossary\/hcistats\/bayesian%20methods\">Bayesian reasoning<\/a>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/bayesian%20statistics\">Bayesian statistics<\/a>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/bayesian%20test\">Bayesian test<\/a>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/bias\">bias<\/a>, <strong><a href=\"https:\/\/alandix.com\/glossary\/hcistats\/bonferroni%20correction\">Bonferroni correction<\/a><\/strong>, <strong><a href=\"https:\/\/alandix.com\/glossary\/hcistats\/cherry%20picking\">cherry picking<\/a><\/strong>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/closed%20formula\">closed formula<\/a>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/coin%20tossing\">coin tossing<\/a>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/computer%20simulation\">computer simulation<\/a>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/confidence%20interval\">confidence interval<\/a>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/confirmation%20bias\">confirmation bias<\/a>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/continuous%20distribution\">continuous distribution<\/a>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/emergent%20patterns\">emergent patterns<\/a>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/empirical%20data\">empirical data<\/a>, <strong><a href=\"https:\/\/alandix.com\/glossary\/hcistats\/empirical%20methods\">empirical methods<\/a><\/strong>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/estimated%20standard%20deviation\">estimated standard deviation<\/a>, <strong><a href=\"https:\/\/alandix.com\/glossary\/hcistats\/extreme%20statistics\">extreme statistics<\/a><\/strong>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/extreme%20values\">extreme values<\/a>, <strong><a href=\"https:\/\/alandix.com\/glossary\/hcistats\/factorial\">factorial<\/a><\/strong>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/fair%20coin\">fair coin<\/a>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/false%20negative\">false negative<\/a>, <strong><a href=\"https:\/\/alandix.com\/glossary\/hcistats\/file%20drawer%20effect\">file drawer effect<\/a><\/strong>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/fishing%20expedition\">fishing expedition<\/a>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/hypothesis%20testing\">hypothesis testing<\/a>, <strong><a href=\"https:\/\/alandix.com\/glossary\/hcistats\/inter-related%20factors\">inter-related factors<\/a><\/strong>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/likelihood\">likelihood<\/a>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/machine%20learning\">machine learning<\/a>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/mathematics\">mathematics<\/a>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/mean\">mean (&amp;mu;)<\/a>, <strong><a href=\"https:\/\/alandix.com\/glossary\/hcistats\/multiple%20statistics\">multiple statistics<\/a><\/strong>, <strong><a href=\"https:\/\/alandix.com\/glossary\/hcistats\/multiple%20tests\">multiple tests<\/a><\/strong>, <strong><a href=\"https:\/\/alandix.com\/glossary\/hcistats\/multiplicity%20control\">multiplicity control<\/a><\/strong>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/negative%20results\">negative results<\/a>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/network%20data\">network data<\/a>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/non-significant%20result\">non-significant result<\/a>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/nonparametric%20statistics\">nonparametric statistics<\/a>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/normal%20distribution\">Normal distribution<\/a>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/not%20independent\">not independent<\/a>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/null%20hypothesis\">null hypothesis<\/a>, <strong><a href=\"https:\/\/alandix.com\/glossary\/hcistats\/numeric%20data\">numeric data<\/a><\/strong>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/odds%20ratio\">odds ratio<\/a>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/one-tailed%20test\">one-tailed test<\/a>, <strong><a href=\"https:\/\/alandix.com\/glossary\/hcistats\/outliers\">outliers<\/a><\/strong>, <strong><a href=\"https:\/\/alandix.com\/glossary\/hcistats\/p-curve\">p-curve<\/a><\/strong>, <strong><a href=\"https:\/\/alandix.com\/glossary\/hcistats\/p-hacking\">p-hacking<\/a><\/strong>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/p-value\">p-value<\/a>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/positive%20results\">positive results<\/a>, <strong><a href=\"https:\/\/alandix.com\/glossary\/hcistats\/post-hoc%20hypothesis\">post-hoc hypothesis<\/a><\/strong>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/posterior%20distribution\">posterior distribution<\/a>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/power-law%20distribution\">power-law distribution<\/a>, <strong><a href=\"https:\/\/alandix.com\/glossary\/hcistats\/pre-registration\">pre-registration<\/a><\/strong>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/prior%20distribution\">prior distribution<\/a>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/probability%20distribution\">probability distribution<\/a>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/r\">R<\/a>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/removing%20outliers\">removing outliers<\/a>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/response%20time\">response time<\/a>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/sample\">sample<\/a>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/sample%20variance\">sample variance<\/a>, <strong><a href=\"https:\/\/alandix.com\/glossary\/hcistats\/selective%20publishing\">selective publishing<\/a><\/strong>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/significance\">significance<\/a>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/significance%20level\">significance level<\/a>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/significance%20test\">significance test<\/a>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/significant%20range\">significant range<\/a>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/significant%20result\">significant result<\/a>, <strong><a href=\"https:\/\/alandix.com\/glossary\/hcistats\/simulation%20methods\">simulation methods<\/a><\/strong>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/social%20network%20data\">social network data<\/a>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/spss\">SPSS<\/a>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/standard%20deviation\">standard deviation (s.d., &amp;sigma;)<\/a>, <strong><a href=\"https:\/\/alandix.com\/glossary\/hcistats\/starting%20hypothesis\">starting hypothesis<\/a><\/strong>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/statistical%20power\">statistical power<\/a>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/statistical%20significance\">statistical significance<\/a>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/statistically%20significant\">statistically significant<\/a>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/statistically%20significant%20effect\">statistically significant effect<\/a>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/student%27s%20t%20distribution\">Student&#039;s t distribution<\/a>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/student%27s%20t-test\">Student&#039;s t-test<\/a>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/systematic%20effects\">systematic effects<\/a>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/task%20completion%20time\">task completion time<\/a>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/theoretical%20distribution\">theoretical distribution<\/a>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/traditional%20statistics\">traditional statistics<\/a>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/two-tailed%20test\">two-tailed test<\/a>, <strong><a href=\"https:\/\/alandix.com\/glossary\/hcistats\/type%20ii%20error\">Type II error<\/a><\/strong>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/uniform%20prior\">uniform prior<\/a>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/user%20experience\">user experience<\/a>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/user%20interface\">user interface<\/a>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/user%20interface%20properties\">user interface properties<\/a>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/user%20test\">user test<\/a>, <a href=\"https:\/\/alandix.com\/glossary\/hcistats\/variance\">variance<\/a><\/div>\n\n\n<!-- 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