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hypothesis test that regression estimate non zero constant

laura_ellman1

Community Trekker

Joined:

Jul 29, 2014

If I want to test that a regression parameter b is equal to a nonzero constant, is there a script for that?

For example, in the Pendulum sample data available in JMP, let's say I fit Period = b + m*sqrt(Length).   I want to test the hypothesis that m=2.   The output tests whether m=0, which may not be that interesting.

Is there a script to test whether a parameter estimate is equal to some non-zero constant?

1 REPLY
Dan_Obermiller

Joined:

Apr 3, 2013

Not a script, but it would be fairly easy to create one.

Easiest, quickest solution is to right-click on the Parameter Estimates table and choose the Lower and Upper 95% confidence limits. This will show you the 95% confidence interval for parameter estimate. If that interval contains the nonzero constant, then you have a non-significant result. If the nonzero constant is outside of the interval, then you have a statistically significant difference from that constant.

A simple formula script would look something like this:

df==1;

Estimate==1;

Constant==2;

Std_Error=0.625;

t_Ratio == (Estimate - Constant) / Std_Error;

p_value==If(t_Ratio >= 0, (1 - t Distribution(t_ Ratio, df)) * 2, t Distribution(t_Ratio, df) * 2);

You can certainly make this much fancier with dialogs and such or even reading directly from a report, but this is the essence of the formulas that would work.

Dan Obermiller