{"id":53,"date":"2021-12-22T23:09:00","date_gmt":"2021-12-22T21:09:00","guid":{"rendered":"https:\/\/mat.uab.cat\/web\/sea\/?p=53"},"modified":"2022-01-13T18:02:23","modified_gmt":"2022-01-13T16:02:23","slug":"sample-size","status":"publish","type":"post","link":"https:\/\/mat.uab.cat\/web\/sea\/2021\/12\/22\/sample-size\/","title":{"rendered":"Sample Size"},"content":{"rendered":"<p>When designing a study, determining the sample size is a critical decision.<\/p>\n<p>In order to estimate the population average from a sample of units, by means of a confidence interval at the 1-alpha level, that provides a particular precission; we can use the following formula to compute the amount of units that would be needed:<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-medium\" src=\"http:\/\/mat.uab.cat\/web\/sea\/wp-content\/uploads\/sites\/27\/2022\/01\/imatge.png\" width=\"234\" height=\"120\" \/><\/p>\n<p>In order to evaluate the mean difference between two groups in a given population from a sample of units, when the comparison will be performed by means of a Z-test with a significance level (alpha); the following formula will provide the number of units per group to achieve a given statistical power (1-beta):<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"size-medium aligncenter\" src=\"http:\/\/mat.uab.cat\/web\/sea\/wp-content\/uploads\/sites\/27\/2022\/01\/imatge-1.png\" width=\"367\" height=\"114\" \/><\/p>\n<p>Ene 3.0 is a software aimed to solve the sample size problem when designing studies for a wide range of experimental designs and objectives. You can obtain a free copy writing an email to: <a href=\"mailto:s.estadistica@uab.cat\">s.estadistica@uab.cat<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>When designing a study, determining the sample size is a critical decision. In order to estimate the population average from a sample of units, by means of a confidence interval at the 1-alpha level, that provides a particular precission; we can use the following formula to compute the amount of units that would be needed:&hellip; <a class=\"more-link\" href=\"https:\/\/mat.uab.cat\/web\/sea\/2021\/12\/22\/sample-size\/\">Continueu llegint <span class=\"screen-reader-text\">Sample Size<\/span><\/a><\/p>\n","protected":false},"author":37,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-53","post","type-post","status-publish","format-standard","hentry","category-general","entry"],"_links":{"self":[{"href":"https:\/\/mat.uab.cat\/web\/sea\/wp-json\/wp\/v2\/posts\/53","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/mat.uab.cat\/web\/sea\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mat.uab.cat\/web\/sea\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mat.uab.cat\/web\/sea\/wp-json\/wp\/v2\/users\/37"}],"replies":[{"embeddable":true,"href":"https:\/\/mat.uab.cat\/web\/sea\/wp-json\/wp\/v2\/comments?post=53"}],"version-history":[{"count":3,"href":"https:\/\/mat.uab.cat\/web\/sea\/wp-json\/wp\/v2\/posts\/53\/revisions"}],"predecessor-version":[{"id":154,"href":"https:\/\/mat.uab.cat\/web\/sea\/wp-json\/wp\/v2\/posts\/53\/revisions\/154"}],"wp:attachment":[{"href":"https:\/\/mat.uab.cat\/web\/sea\/wp-json\/wp\/v2\/media?parent=53"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mat.uab.cat\/web\/sea\/wp-json\/wp\/v2\/categories?post=53"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mat.uab.cat\/web\/sea\/wp-json\/wp\/v2\/tags?post=53"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}