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Comparing different processes with t tests


Does anybody know how to compare different processes using t-test in JMP?

I've seen reports such as the one shown below where defect levels from three different processes are shown in columns on the left of a report and the spreads are represented by bubbles on the right of the report.

For any given process the data points are represented by a diamond showing upper quartile, median and lower quartile. The diameter of the bubbles on the right represent the standard deviation.

Bubbles that do not overlap indicate that the difference between the two processes being compared is statistically significant.


I think your understanding of the diamonds and circles is not correct, and JMP help has a description of what the diamonds and circles mean.

To create such a plot in JMP, you would go to Analyze>Fit Y by X and make X a nominal or ordinal variable.
Thanks Paige,

How does one run a t-test on two different populations where the populations can be compared side by side to a given confidence level.

Could you see the example I had posted? It shows quartiles for each population on the left and std deviation "bubbles" on the right. I've seen these kinds of reports before but dont know how to create one from scratch.


Please be more specific. I already explained how to do this. In JMP, Go to Analyze>Fit Y by X and make X a nominal or ordinal variable.

If you don't understand, please ask a more detailed question.

And again, your explanation of the plots is not correct. The diamonds do not show quartiles. The circles on the right are comparison circles, not standard deviation circles. The JMP documentation has explanations of these plots.
Thanks Paige,

You are correct. I was misinterpretting these plots.

I found a good tutorial called "Many Means" and it walked me through the plots.