{"id":474,"date":"2016-03-18T22:28:28","date_gmt":"2016-03-18T22:28:28","guid":{"rendered":"http:\/\/marcelloricottone.com\/blog\/?p=474"},"modified":"2016-03-18T22:28:28","modified_gmt":"2016-03-18T22:28:28","slug":"journal-club-week-of-3182016","status":"publish","type":"post","link":"https:\/\/marcelloricottone.com\/blog\/2016\/03\/18\/journal-club-week-of-3182016\/","title":{"rendered":"Journal Club: Week of 3\/18\/2016"},"content":{"rendered":"<p>The ASA&#8217;s statement on p-values: context, process, and purpose<\/p>\n<div>Ronald L. Wasserstein & Nicole A. Lazar<\/div>\n<div><\/div>\n<div>P-values are a hotly debated topic recently. Al throughout school I learned that a p value of 0.05 makes or breaks any scientific progress. This paper, in the form of a statement from American Statistical Association, lays out all the flaws and common misuse of p-values. THe article starts with the motivation of the statement, this is a rare move for the ASA. This lends a little gravity to the paper. The statement; however, is where all the interesting parts lie. In the statement, there is a little obtuse definition of P value, quoted below:<\/div>\n<div><\/div>\n<div>&#8220;Informally, a p-value is the probability under a specified statistical model that a statistical summary of the data (for example, the sample mean difference between two compared groups would be equal to or more extreme than its observed value.&#8221;<\/div>\n<div><\/div>\n<div>Not exactly the clearest definition. However, the power of this paper lies in the Principles section. ASA outlines 6 principles of proper usage of p-values: replicated in the list below:<\/div>\n<div><\/div>\n<div>1. P-values can indicate how incompatible the data are with a specified statistical model<\/div>\n<div>2.P-values do not measure the probability that the studied hypothesis is true, or the probability that the data were produced by random chance alone.<\/div>\n<div>3. Scientific conclusions and business or policy decision should not be based only on whether a p-value passes a specific threshold<\/div>\n<div>4. proper inference requires full reporting and transparency<\/div>\n<div>5. a p-value, or statistical significance, does not measure the size of an effect or the importance of a result<\/div>\n<div>6. By itself, a p-value does not provide a good measure of evidence regarding a model or hypothesis.<\/div>\n<div>\n<div><\/div>\n<div>Wow, everyone who works with p-values should have to recite these rules before they begin their analysis. They should have them framed above their desk. I know in the past I have gone against 2,5, and 6. I highly suggest reading this statement. It will take you less than 20 minutes. If you cant spare that, just read the last line:<\/div>\n<div><\/div>\n<div>&#8220;No single index should substitute for scientific reasoning&#8221;<\/div>\n<\/div>\n<div>&#8211; Marcello<\/div>\n","protected":false},"excerpt":{"rendered":"<p>The ASA&#8217;s statement on p-values: context, process, and purpose Ronald L. Wasserstein &#038; Nicole A. Lazar P-values are a hotly debated topic recently. Al throughout school I learned that a p value of 0.05 makes or breaks any scientific progress. This paper, in the form of a statement from American Statistical Association, lays out all&hellip; <\/p>\n<p class=\"toivo-read-more\"><a href=\"https:\/\/marcelloricottone.com\/blog\/2016\/03\/18\/journal-club-week-of-3182016\/\" class=\"more-link\">Read more <span class=\"screen-reader-text\">Journal Club: Week of 3\/18\/2016<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":{"0":"post-474","1":"post","2":"type-post","3":"status-publish","4":"format-standard","6":"category-allposts","7":"entry"},"_links":{"self":[{"href":"https:\/\/marcelloricottone.com\/blog\/wp-json\/wp\/v2\/posts\/474","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/marcelloricottone.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/marcelloricottone.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/marcelloricottone.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/marcelloricottone.com\/blog\/wp-json\/wp\/v2\/comments?post=474"}],"version-history":[{"count":1,"href":"https:\/\/marcelloricottone.com\/blog\/wp-json\/wp\/v2\/posts\/474\/revisions"}],"predecessor-version":[{"id":475,"href":"https:\/\/marcelloricottone.com\/blog\/wp-json\/wp\/v2\/posts\/474\/revisions\/475"}],"wp:attachment":[{"href":"https:\/\/marcelloricottone.com\/blog\/wp-json\/wp\/v2\/media?parent=474"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/marcelloricottone.com\/blog\/wp-json\/wp\/v2\/categories?post=474"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/marcelloricottone.com\/blog\/wp-json\/wp\/v2\/tags?post=474"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}