Comments on: How to compare multi-row averages in JMP?
http://ask.metafilter.com/67549/How-to-compare-multirow-averages-in-JMP/
Comments on Ask MetaFilter post How to compare multi-row averages in JMP?Sun, 22 Jul 2007 16:00:50 -0800Sun, 22 Jul 2007 16:00:50 -0800en-ushttp://blogs.law.harvard.edu/tech/rss60Question: How to compare multi-row averages in JMP?
http://ask.metafilter.com/67549/How-to-compare-multirow-averages-in-JMP
How do I compare averages in JMP (statistical software)? Help me stop using Excel. <br /><br /> I have a behavioral data file where each row is an individual response time measurement. Each row contains three fields: <i>subject</i> (numeric, nominal); <i>stimulus</i> (character, nominal); <i>RT</i> (numeric, continuous). The file contains hundreds of rows per subject (equal number of stimuli-rows per subject), and dozens of subjects.<br>
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I'm pretty certain that what I'm supposed to do here is a repeated measures ANOVA. For each subject-stimulus pair, obtain an RT average, thus ending up with (n subjects * n stims) averages. I then do the ANOVA on that.<br>
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So, what I've been doing is using an Excel Pivottable to collapse/average across subject-stimulus, and then taking the resulting data into JMP for the ANOVA. This seems really silly to me - there's got to be a way to do this all in JMP, probably in just one or two steps, without all this copying and pasting, if I just knew what I was doing.<br>
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How might I do that?post:ask.metafilter.com,2007:site.67549Sun, 22 Jul 2007 14:40:31 -0800dmdstatisticsexceljmppivottableanovaBy: a robot made out of meat
http://ask.metafilter.com/67549/How-to-compare-multirow-averages-in-JMP#1012165
The JMP website says that it's from SAS, so perhaps it will accept the same commands as SAS? <a href="http://www.ats.ucla.edu/STAT/sas/library/repeated_ut.htm"> This is an exhaustive walkthrough of that task in SAS. </a> If not, the website seems to indicate that it's mostly a visualization software. You might want to invest in actual SAS or something else (R is free, and easy to do this in).comment:ask.metafilter.com,2007:site.67549-1012165Sun, 22 Jul 2007 16:00:50 -0800a robot made out of meatBy: a robot made out of meat
http://ask.metafilter.com/67549/How-to-compare-multirow-averages-in-JMP#1012176
Also, googling "jmp anova repeated measures" pulls up relevant things at #1 and #2.comment:ask.metafilter.com,2007:site.67549-1012176Sun, 22 Jul 2007 16:19:06 -0800a robot made out of meatBy: myeviltwin
http://ask.metafilter.com/67549/How-to-compare-multirow-averages-in-JMP#1012199
If I understand you correctly, I think you can do this with a summary table.<br>
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Here's the step-by-step:<br>
1. From the raw data table, choose Table > Summary.<br>
2. Click on RT and under "Statistics" select mean.<br>
3. Drag "Subject" to the "Group" box.<br>
4. Drag "stimulus" to the "Subgroup" box.<br>
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Click OK, and you should get a new table with the data arranged properly.comment:ask.metafilter.com,2007:site.67549-1012199Sun, 22 Jul 2007 16:59:04 -0800myeviltwinBy: dmd
http://ask.metafilter.com/67549/How-to-compare-multirow-averages-in-JMP#1012219
myeviltwin: Thanks, your answer lets me do the equivalent of pivottables in jmp.<br>
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I still feel like there should be a way to do this without that intermediate step at all, though. I don't really follow what's going on in what a.r.m.o.o.m. pointed to (which is probably a bad sign as far as my understanding of what I'm doing goes) ...comment:ask.metafilter.com,2007:site.67549-1012219Sun, 22 Jul 2007 17:24:55 -0800dmdBy: a robot made out of meat
http://ask.metafilter.com/67549/How-to-compare-multirow-averages-in-JMP#1012270
dmd, the ins-and-outs of the many kinds of anovas, why, when, and how they work etc. is a very complicated topic. How to use the last generation of statistical software (which JMP is built off of, but it apparently much friendlier) is also pretty tough. The need for great control and flexibility by professionals lead to a hard learning curve and tough controls. If the long explanation I linked is confusion, that's probably because it's not targeted enough at what you want.<br>
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Also, I like AROOM better than my actual handle.comment:ask.metafilter.com,2007:site.67549-1012270Sun, 22 Jul 2007 18:47:35 -0800a robot made out of meatBy: hydropsyche
http://ask.metafilter.com/67549/How-to-compare-multirow-averages-in-JMP#1012758
I use JMP all the time. For those who aren't familiar, it is made by SAS, but uses a GUI to access SAS functions rather than a command line. <br>
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If I understand your question, you're more interested in running ANOVA than in just finding the means, as with the summary function. You can do ANOVA directly from the data you've described with one step in JMP. Under the Analyze menu, choose "Fit Y by X". Make RT your response and both subject and stimulus your factors. On the output screen, you can get it to run Student's t-test and various other types of tests, in addition to ANOVA.comment:ask.metafilter.com,2007:site.67549-1012758Mon, 23 Jul 2007 09:43:13 -0800hydropsycheBy: dmd
http://ask.metafilter.com/67549/How-to-compare-multirow-averages-in-JMP#1013086
hydropsyche, I'm pretty sure that's specifically forbidden. All of those individual RT measurements don't 'count' as observations - they are values whose <i>mean</i> is an observation.comment:ask.metafilter.com,2007:site.67549-1013086Mon, 23 Jul 2007 14:27:54 -0800dmdBy: hydropsyche
http://ask.metafilter.com/67549/How-to-compare-multirow-averages-in-JMP#1013933
Sorry, this is pretty different data from what I do. If that's the case, then I think you're stuck using the summary table and then running ANOVA on that. 2 steps in JMP beats cutting and pasting from Excel.comment:ask.metafilter.com,2007:site.67549-1013933Tue, 24 Jul 2007 08:42:04 -0800hydropsyche