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Equivalence Test for Means: Adjust Confidence Intervals for the Differences?

Hello together,

I'm new to jmp17 and tried to do a TOST Test.

In Fit Y by X, I selected Equivalence Test --> Means.

Regarding the Forest Plot I wondered if the 90% Confidence Intervals for the Difference is the error bar in the plot and if there is a way to adjust the confidence interval?

CoxPanther919_1-1679927278702.png

Thanks!

 

 

1 ACCEPTED SOLUTION

Accepted Solutions
Victor_G
Super User

Re: Equivalence Test for Means: Adjust Confidence Intervals for the Differences?

Hi @CoxPanther919,

 

Welcome in the Community !

 

Yes, the error bar represents the 90% confidence interval of the TOST you have realized.

Since you're doing a Two One-Sided Test, each one-sided test will use the alpha you have specified in the launch window (0,05 by default, so confidence level = 0,95), but you're doing two comparisons in a TOST : one for superior value, one for inferior value, so your "global" confidence for the TOST is 0,95 to the power of 2 (2 tests or comparisons done) = 0,90.

 

If you would like to have a 95% interval confidence, you will have to specify an alpha value of 0,025 (or say otherwise, confidence level of 0,975 for each test) : 0,975^2 = 0,95.

 

One practical example here :

Victor_G_0-1679929991750.png

Result :

Victor_G_1-1679930036522.png

 

I hope I understood your question and that this answer will help you,

Victor GUILLER
Scientific Expertise Engineer
L'Oréal - Data & Analytics

View solution in original post

3 REPLIES 3
David_Burnham
Super User (Alumni)

Re: Equivalence Test for Means: Adjust Confidence Intervals for the Differences?

In the dialog, when you enter the "difference" value, you can also enter the alpha-level.  This will control the confidence interval width.

-Dave
Victor_G
Super User

Re: Equivalence Test for Means: Adjust Confidence Intervals for the Differences?

Hi @CoxPanther919,

 

Welcome in the Community !

 

Yes, the error bar represents the 90% confidence interval of the TOST you have realized.

Since you're doing a Two One-Sided Test, each one-sided test will use the alpha you have specified in the launch window (0,05 by default, so confidence level = 0,95), but you're doing two comparisons in a TOST : one for superior value, one for inferior value, so your "global" confidence for the TOST is 0,95 to the power of 2 (2 tests or comparisons done) = 0,90.

 

If you would like to have a 95% interval confidence, you will have to specify an alpha value of 0,025 (or say otherwise, confidence level of 0,975 for each test) : 0,975^2 = 0,95.

 

One practical example here :

Victor_G_0-1679929991750.png

Result :

Victor_G_1-1679930036522.png

 

I hope I understood your question and that this answer will help you,

Victor GUILLER
Scientific Expertise Engineer
L'Oréal - Data & Analytics

Re: Equivalence Test for Means: Adjust Confidence Intervals for the Differences?

Hi @Victor_G ,

 

thank you very much, this was exactly my question!

 

Best regards