Example of the Robust Fit Option

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Basic Analysis • Oneway Analysis • Additional Examples of the Oneway Platform • Example of the Robust Fit Option

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Example of the Robust Fit Option

The data in the Drug Toxicity.jmp sample data table shows the toxicity levels for three different formulations of a drug.

1.

Select Help > Sample Data Library and open Drug Toxicity.jmp.

2.

Select Analyze > Fit Y by X.

3.

Select Toxicity and click Y, Response.

4.

Select Formulation and click X, Factor.

5.

6.

From the red triangle menu, select Means/Anova.

7.

From the red triangle menu, select Robust > Robust Fit.

Figure 6.31 Example of Robust Fit

If you look at the standard Analysis of Variance report, you might wrongly conclude that there is a difference between the three formulations, since the p-value is 0.0319. However, when you look at the Robust Fit report, you would not conclude that the three formulations are significantly different, because the p-value there is 0.21755. It appears that the toxicity for a few of the observations is unusually high, creating the undue influence on the data.

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Help created on 3/19/2020