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Ttests

dmahan1

Community Trekker

Joined:

Jul 10, 2014

I routinely perform ttests on unpaired and independent data sets.  The dropdown in the oneway analysis report allows you to select for paired ttest.  I am aware of the ANOM feature, but would still like to perform a ttest on independent data.  Does JMP provide this feature.

1 REPLY
julian

Staff

Joined:

Jun 25, 2014

Hi dmahan1,

The t-test options available in Fit Y by X (with a nominal X and continuous Y) are all for independent samples (both Means/ANOVA, and t-test compute independent samples t-test, assuming equal variance and not assuming equal variance respectively). The options under "Compare Means" are not for paired tests, but for pair-wise tests (comparisons of pairs of means, treated as independent samples). For independent measures tests, data must be arranged to have a single column for the response variable, and another variable (nominal) that identifies groups. For example:

Name         Final Exam     Training Group

John          87                     Experimental

Timmy       76                     Experimental

Gloria         88                    Control

...

For paired t-tests, you can use the "Matched Pairs" platform. For this platform data must be arranged to have paired observations in two columns. For example:

Name         Test 1    Test 2

John          15          20

Timmy       25          28

Gloria         31          32

I hope this helps!

Julian