{"id":6739,"date":"2024-01-09T01:00:02","date_gmt":"2024-01-09T08:00:02","guid":{"rendered":"https:\/\/www.qimacros.com\/lean-six-sigma-blog\/?p=6739"},"modified":"2023-11-14T16:02:57","modified_gmt":"2023-11-14T23:02:57","slug":"line-charts-with-trend-lines-are-fake-news","status":"publish","type":"post","link":"https:\/\/www.qimacros.com\/lean-six-sigma-blog\/line-charts-with-trend-lines-are-fake-news\/","title":{"rendered":"Line Charts with Trend Lines are Fake News"},"content":{"rendered":"\r\n<p>Line charts with trend lines are fake news. Here&#8217;s why:<\/p>\r\n\r\n\r\n\r\n<p><iframe loading=\"lazy\" src=\"https:\/\/player.vimeo.com\/video\/869252872?title=0&amp;byline=0&amp;portrait=0\" width=\"720\" height=\"405\" frameborder=\"0\" allowfullscreen=\"allowfullscreen\"><span data-mce-type=\"bookmark\" style=\"display: inline-block; width: 0px; overflow: hidden; line-height: 0;\" class=\"mce_SELRES_start\">\ufeff<\/span><\/iframe><\/p>\r\n\r\n\r\n\r\n<p>Download my free ebook <a href=\"https:\/\/www.qimacros.com\/pdf\/Agile-Process-Innovation.pdf\" target=\"_blank\" rel=\"noopener\">Agile Process Innovation<\/a>.<\/p>\r\n<p>&#8220;Hi, I&#8217;m Jay Arthur, author of \u201c<a href=\"https:\/\/www.amazon.com\/Lean-Six-Sigma-Hospitals-Improving\/dp\/1259641082\/\">Lean Six Sigma For Hospitals<\/a>\u201d and\u00a0<a href=\"https:\/\/www.qimacros.com\/demo\/\">QI Macros [software]<\/a>.<\/p>\r\n<p>&#8220;I was at the Institute for Healthcare Improvement conference, and I go through and I look at all the post-improvement posters that are out there. I saw \u201cNurse Betty\u201d (that&#8217;s what I&#8217;m going to call her) and she was standing in front of a poster and she was studying it. She was wearing a nice blue pantsuit [and] comfortable shoes because it&#8217;s a lot of walking in these conferences, but she was staring at it like crazy. She pulls out her cell phone she takes a picture of this improvement poster, and so I thought, \u201cWell, I guess I better go find out what Nurse Betty was doing,\u201d right? What was she looking at?<\/p>\r\n<p>&#8220;I went over there and it turned out there was a line chart about reducing a certain kind of infection in a hospital (I think it was urinary tract infections or something). Fortunately, they put the numbers on there so I took a picture of it and I went back and actually put together a line chart. The chart on the poster had a trend line through it that looked like \u201cOh yeah, we&#8217;ve reduced infections, yay!\u201d right? So I went ahead and I did it\u2026 but then unlike theirs, I put the trend line in but I added the goodness of fit metric called r squared. Now r squared was only 0.32 or 32 percent fit. Would you want to stake your reputation on a 32 percent fit? No! You know, once it gets over 50 it&#8217;s a little bit better, once it gets to 80 that&#8217;s a pretty good fit. I have seen one or two line graphs with trend lines there where the r squared (not shown on the chart, I might add) the r squared was over 80\u2026 sweet! I could trust that one.<\/p>\r\n<p>&#8220;So what I want you to do is get this idea if you see a line graph with a trend line on it that&#8217;s fake news. You don&#8217;t know anything at all about that trend line; Excel will fit a trend line to anything. You know, I&#8217;ve seen trend lines where it was&#8230; you know, like six percent fit, but Excel will throw one on there for you. It doesn&#8217;t mean it&#8217;s good, it didn&#8217;t mean you got better, it might just mean that you faked yourself out.<\/p>\r\n<p>&#8220;So next time you see a line chart with a trend line on it and no r squared value, you can just assume it&#8217;s fake news. It&#8217;s much easier to use a control chart, and then you can see if it actually had some sort of actual change.<\/p>\r\n<p>&#8220;So that&#8217;s my Improvement Insight for this week: Line charts with trend lines are fake news. Same thing with bar charts, I might add. Start using control charts. They&#8217;ve been around for 100 years. Let&#8217;s all start using them.<\/p>\r\n<p>&#8220;Let&#8217;s create a hassle-free America; hassle-free healthcare. Let&#8217;s go out and improve something this week. &#8220;<\/p>\r\n","protected":false},"excerpt":{"rendered":"<p>Line charts with trend lines are fake news. Here&rsquo;s why: &#65279; Download my free ebook Agile Process Innovation. &ldquo;Hi, I&rsquo;m Jay Arthur, author of &ldquo;Lean Six Sigma For Hospitals&rdquo; and&nbsp;QI Macros [software]. &ldquo;I was at the Institute for Healthcare Improvement conference, and I go through and I look at all the post-improvement posters that are [&hellip;]<\/p>\n","protected":false},"author":4,"featured_media":6814,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[290],"tags":[41,442,328,168,441],"class_list":["post-6739","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-improvement-insights","tag-excel","tag-fake-news","tag-line-chart","tag-qi-macros","tag-trend-line"],"_links":{"self":[{"href":"https:\/\/www.qimacros.com\/lean-six-sigma-blog\/wp-json\/wp\/v2\/posts\/6739","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.qimacros.com\/lean-six-sigma-blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.qimacros.com\/lean-six-sigma-blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.qimacros.com\/lean-six-sigma-blog\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/www.qimacros.com\/lean-six-sigma-blog\/wp-json\/wp\/v2\/comments?post=6739"}],"version-history":[{"count":5,"href":"https:\/\/www.qimacros.com\/lean-six-sigma-blog\/wp-json\/wp\/v2\/posts\/6739\/revisions"}],"predecessor-version":[{"id":6832,"href":"https:\/\/www.qimacros.com\/lean-six-sigma-blog\/wp-json\/wp\/v2\/posts\/6739\/revisions\/6832"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.qimacros.com\/lean-six-sigma-blog\/wp-json\/wp\/v2\/media\/6814"}],"wp:attachment":[{"href":"https:\/\/www.qimacros.com\/lean-six-sigma-blog\/wp-json\/wp\/v2\/media?parent=6739"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.qimacros.com\/lean-six-sigma-blog\/wp-json\/wp\/v2\/categories?post=6739"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.qimacros.com\/lean-six-sigma-blog\/wp-json\/wp\/v2\/tags?post=6739"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}