﻿{"id":978,"date":"2012-11-24T14:39:55","date_gmt":"2012-11-24T05:39:55","guid":{"rendered":"http:\/\/fujiitoshiki.com\/improvesociety\/?p=978"},"modified":"2017-04-27T12:43:46","modified_gmt":"2017-04-27T03:43:46","slug":"when-should-you-execute-fisher-exact-test-not-chi-square-test","status":"publish","type":"post","link":"https:\/\/www.fujiitoshiki.com\/improvesociety\/?p=978","title":{"rendered":"When should you execute Fisher exact test, not chi-square test?"},"content":{"rendered":"<div class=\"theContentWrap-ccc\"><p> You should not execute chi-square test but Fisher exact probability test when gland total of cross tabulation was smaller than 20 or one or greater than one cells had smaller than 5 expected value. In this article, I would like to describe how to solve expected value. Expected value is calculated with marginal total. <\/p>\n<p> We have cross tabulation below;<\/p>\n<table border=\"0\" align=\"left\">\n<tbody>\n<tr style=\"background-color: #a9a9a9;\">\n<td style=\"background-color: #a9a9a9;\">\u00a0<\/td>\n<td align=\"center\" valign=\"middle\"><strong><span style=\"font-size: small; font-family: georgia, palatino; color: #ffffff;\">TRUE<\/span><\/strong><\/td>\n<td align=\"center\" valign=\"middle\"><strong><span style=\"font-size: small; font-family: georgia, palatino; color: #ffffff;\">FALSE<\/span><\/strong><\/td>\n<td style=\"background-color: #a9a9a9;\" align=\"center\" valign=\"middle\"><span style=\"font-size: small; font-family: georgia, palatino; color: #ffffff;\">Marginal total<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"background-color: #a9a9a9;\"><strong><span style=\"font-size: small; font-family: georgia, palatino; color: #ffffff;\">POSITIVE<\/span><\/strong><\/td>\n<td align=\"center\" valign=\"middle\"><span style=\"font-size: small; font-family: georgia, palatino;\">a<\/span><\/td>\n<td align=\"center\" valign=\"middle\"><span style=\"font-family: georgia, palatino; font-size: small;\"><span style=\"line-height: 19px;\">b<\/span><\/span><\/td>\n<td style=\"background-color: #a9a9a9;\" align=\"center\" valign=\"middle\"><span style=\"font-size: small; font-family: georgia, palatino; color: #ffffff;\">a + b<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"background-color: #a9a9a9;\"><strong><span style=\"font-size: small; font-family: georgia, palatino; color: #ffffff;\">NEGATIVE<\/span><\/strong><\/td>\n<td align=\"center\" valign=\"middle\"><span style=\"font-size: small; font-family: georgia, palatino;\">c<\/span><\/td>\n<td align=\"center\" valign=\"middle\"><span style=\"font-size: small; font-family: georgia, palatino;\">d<\/span><\/td>\n<td style=\"background-color: #a9a9a9;\" align=\"center\" valign=\"middle\"><span style=\"font-size: small; font-family: georgia, palatino; color: #ffffff;\">c + d<\/span><\/td>\n<\/tr>\n<tr style=\"background-color: #a9a9a9;\">\n<td style=\"background-color: #a9a9a9;\"><span style=\"font-size: small; font-family: georgia, palatino; color: #ffffff;\">Marginal total<\/span><\/td>\n<td align=\"center\" valign=\"middle\"><span style=\"font-size: small; font-family: georgia, palatino; color: #ffffff;\">a + c<\/span><\/td>\n<td align=\"center\" valign=\"middle\"><span style=\"font-size: small; font-family: georgia, palatino; color: #ffffff;\">b + d<\/span><\/td>\n<td align=\"center\" valign=\"middle\"><span style=\"font-size: small; font-family: georgia, palatino; color: #ffffff;\">N<\/span>\u00a0<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p> Expected value of each cells is below;<\/p>\n<table border=\"0\" align=\"left\">\n<tbody>\n<tr style=\"background-color: #a9a9a9;\">\n<td style=\"background-color: #a9a9a9;\">\u00a0<\/td>\n<td align=\"center\" valign=\"middle\"><strong><span style=\"font-size: small; font-family: georgia, palatino; color: #ffffff;\">TRUE<\/span><\/strong><\/td>\n<td align=\"center\" valign=\"middle\"><strong><span style=\"font-size: small; font-family: georgia, palatino; color: #ffffff;\">FALSE<\/span><\/strong><\/td>\n<td style=\"background-color: #a9a9a9;\" align=\"center\" valign=\"middle\"><span style=\"font-size: small; font-family: georgia, palatino; color: #ffffff;\">Marginal total<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"background-color: #a9a9a9;\"><strong><span style=\"font-size: small; font-family: georgia, palatino; color: #ffffff;\">POSITIVE<\/span><\/strong><\/td>\n<td align=\"center\" valign=\"middle\"><span style=\"font-family: georgia, palatino; font-size: small;\"><span style=\"line-height: 19px;\">(a + b)*(a + c)\/N<\/span><\/span><\/td>\n<td align=\"center\" valign=\"middle\"><span style=\"font-size: small; font-family: georgia, palatino;\">(a + b)*(b + d)\/N<\/span><\/td>\n<td style=\"background-color: #a9a9a9;\" align=\"center\" valign=\"middle\"><span style=\"font-size: small; font-family: georgia, palatino; color: #ffffff;\">a + b<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"background-color: #a9a9a9;\"><strong><span style=\"font-size: small; font-family: georgia, palatino; color: #ffffff;\">NEGATIVE<\/span><\/strong><\/td>\n<td align=\"center\" valign=\"middle\"><span style=\"font-size: small; font-family: georgia, palatino;\">(c + d)*(a + c)\/N<\/span><\/td>\n<td align=\"center\" valign=\"middle\"><span style=\"font-size: small; font-family: georgia, palatino;\">(c + d)*(b + d)\/N<\/span><\/td>\n<td style=\"background-color: #a9a9a9;\" align=\"center\" valign=\"middle\"><span style=\"font-size: small; font-family: georgia, palatino; color: #ffffff;\">c + d<\/span><\/td>\n<\/tr>\n<tr style=\"background-color: #a9a9a9;\">\n<td style=\"background-color: #a9a9a9;\"><span style=\"font-size: small; font-family: georgia, palatino; color: #ffffff;\">Marginal total<\/span><\/td>\n<td align=\"center\" valign=\"middle\"><span style=\"font-size: small; font-family: georgia, palatino; color: #ffffff;\">a + c<\/span><\/td>\n<td align=\"center\" valign=\"middle\"><span style=\"font-size: small; font-family: georgia, palatino; color: #ffffff;\">b + d<\/span><\/td>\n<td align=\"center\" valign=\"middle\"><span style=\"font-size: small; font-family: georgia, palatino; color: #ffffff;\">N<\/span>\u00a0<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><a href=\"\/\/fujiitoshiki.com\/improvesociety\/?p=839\" target=\"_blank\">How to calculate Fisher\u2019s exact test with logarithm?<\/a><\/p>\n<\/div>","protected":false},"excerpt":{"rendered":"<p>You should not execute chi-square test but Fisher exact probability test when gland total of cross tabulation  &hellip; <a href=\"https:\/\/www.fujiitoshiki.com\/improvesociety\/?p=978\" class=\"more-link\"><span class=\"screen-reader-text\">&#8220;When should you execute Fisher exact test, not chi-square test?&#8221; \u306e<\/span>\u7d9a\u304d\u3092\u8aad\u3080<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_crdt_document":"","_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"categories":[7],"tags":[32,23,56,26],"class_list":["post-978","post","type-post","status-publish","format-standard","hentry","category-statistics","tag-chi-square-test","tag-cross-tabulation","tag-fisher-exact-probability-test","tag-marginal-total"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.fujiitoshiki.com\/improvesociety\/index.php?rest_route=\/wp\/v2\/posts\/978","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.fujiitoshiki.com\/improvesociety\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.fujiitoshiki.com\/improvesociety\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.fujiitoshiki.com\/improvesociety\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.fujiitoshiki.com\/improvesociety\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=978"}],"version-history":[{"count":10,"href":"https:\/\/www.fujiitoshiki.com\/improvesociety\/index.php?rest_route=\/wp\/v2\/posts\/978\/revisions"}],"predecessor-version":[{"id":7715,"href":"https:\/\/www.fujiitoshiki.com\/improvesociety\/index.php?rest_route=\/wp\/v2\/posts\/978\/revisions\/7715"}],"wp:attachment":[{"href":"https:\/\/www.fujiitoshiki.com\/improvesociety\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=978"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.fujiitoshiki.com\/improvesociety\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=978"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.fujiitoshiki.com\/improvesociety\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=978"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}