This example uses the Analgesics.jmp sample data table. Thirty-three subjects were administered three different types of analgesics (A, B, and C). The subjects were asked to rate their pain levels on a sliding scale. You want to find out if the means for A, B, and C are significantly different.
1.
Open the Analgesics.jmp sample data table.
2.
Select Analyze > Fit Y by X.
3.
Select pain and click Y, Response.
4.
Select drug and click X, Factor.
5.
Example of Oneway Analysis
You notice that one drug (A) has consistently lower scores than the other drugs. You also notice that the x-axis ticks are unequally spaced. The length between the ticks is proportional to the number of scores (observations) for each drug.
Note: If the X factor has only two levels, the Means/Anova option appears as Means/Anova/Pooled t, and adds a pooled t-test report to the report window.
Example of the Means/Anova Option
The Analysis of Variance report shows the standard anova information. You notice that the Prob > F (the p-value) is 0.0053, which supports your visual conclusion that there are significant differences between the drugs.