https://communities.sas.com/t5/Statistical-Procedures/How-to-identify-and-remove-outliers/m-p/533791#M26881 <P>The first thing is for you to define clearly to yourself what an "outlier" will be. Typical rules are something like x units of difference from a mean (or median) value. Units of difference might be standard deviations, multiples of the Interquartile range or something else or perhaps the smallest and/or largest x percentage of values.</P> <P>&nbsp;</P> <P>Graphing data is often one way to see if you have values extreme enough that you think they should be eliminated.</P> <P>&nbsp;</P> <P>Once you can do that definition then providing code to do such depends on the type of rule and data involved.</P> Fri, 08 Feb 2019 00:17:14 GMT ballardw 2019-02-08T00:17:14Z https://communities.sas.com/t5/Statistical-Procedures/How-to-identify-and-remove-outliers/m-p/533785#M26880 <P>Could you please help me understand how can I detect and remove outliers? I tried to read the relevant documents but I find difficult to understand.</P> Thu, 07 Feb 2019 23:58:10 GMT https://communities.sas.com/t5/Statistical-Procedures/How-to-identify-and-remove-outliers/m-p/533785#M26880 Babloo 2019-02-07T23:58:10Z https://communities.sas.com/t5/Statistical-Procedures/How-to-identify-and-remove-outliers/m-p/533791#M26881 <P>The first thing is for you to define clearly to yourself what an "outlier" will be. Typical rules are something like x units of difference from a mean (or median) value. Units of difference might be standard deviations, multiples of the Interquartile range or something else or perhaps the smallest and/or largest x percentage of values.</P> <P>&nbsp;</P> <P>Graphing data is often one way to see if you have values extreme enough that you think they should be eliminated.</P> <P>&nbsp;</P> <P>Once you can do that definition then providing code to do such depends on the type of rule and data involved.</P> Fri, 08 Feb 2019 00:17:14 GMT https://communities.sas.com/t5/Statistical-Procedures/How-to-identify-and-remove-outliers/m-p/533791#M26881 ballardw 2019-02-08T00:17:14Z https://communities.sas.com/t5/Statistical-Procedures/How-to-identify-and-remove-outliers/m-p/533796#M26882 Could you please tell me how to graph the data to find the outliers and how<BR />can I eliminate it?<BR /> Fri, 08 Feb 2019 01:00:19 GMT https://communities.sas.com/t5/Statistical-Procedures/How-to-identify-and-remove-outliers/m-p/533796#M26882 Babloo 2019-02-08T01:00:19Z https://communities.sas.com/t5/Statistical-Procedures/How-to-identify-and-remove-outliers/m-p/533798#M26883 <P>There's quite a nice introduction to outliers in this paper which not only covers what they are and how they arise but gives some simple code examples to help you find them -&gt;&nbsp;<A href="https://www.lexjansen.com/nesug/nesug10/ad/ad07.pdf" target="_blank">https://www.lexjansen.com/nesug/nesug10/ad/ad07.pdf</A></P> Fri, 08 Feb 2019 01:03:58 GMT https://communities.sas.com/t5/Statistical-Procedures/How-to-identify-and-remove-outliers/m-p/533798#M26883 ChrisBrooks 2019-02-08T01:03:58Z https://communities.sas.com/t5/Statistical-Procedures/How-to-identify-and-remove-outliers/m-p/533821#M26886 Have you taken the free SAS e-course on Statistics with SAS? If not, it's free and available via e-learning. Fri, 08 Feb 2019 04:00:17 GMT https://communities.sas.com/t5/Statistical-Procedures/How-to-identify-and-remove-outliers/m-p/533821#M26886 Reeza 2019-02-08T04:00:17Z https://communities.sas.com/t5/Statistical-Procedures/How-to-identify-and-remove-outliers/m-p/534582#M26915 <P>See the "Outlier detection" item in the list of <A href="http://support.sas.com/kb/30/333.html" target="_self">Frequently Asked-for Statistics</A> (see the Important Links section).&nbsp;</P> Mon, 11 Feb 2019 19:13:56 GMT https://communities.sas.com/t5/Statistical-Procedures/How-to-identify-and-remove-outliers/m-p/534582#M26915 StatDave 2019-02-11T19:13:56Z