topic Re: Correlation in Matched Pairs Platform in Discussions

Correlation in Matched Pairs Platform

bbenny7 — Thu, 21 Nov 2024 11:00:46 GMT

Hi,

What does the parameter Correlation in the Matched Pairs Platform represent?

I have attached a screeshot from the JMP help website.

Re: Correlation in Matched Pairs Platform

Victor_G — Thu, 21 Nov 2024 12:12:54 GMT

The parameter "Correlation" represents the calculated correlation between pairs of measurements (in the screenshot, between the two responses "Tympanic" and "Oral" measured on the same subjects, hence the "Matched Pairs" analysis).

You'll find your answer in the following JMP Help section : Statistical Details for the Correlation of Responses

Hope this answer will help you,

Re: Correlation in Matched Pairs Platform

jthi — Thu, 21 Nov 2024 12:16:02 GMT

Usually you can get such information from the help page (sometimes it though isn't easy), in this case maybe it is explained here

https://www.jmp.com/support/help/en/18.0/#page/jmp/statistical-details-for-the-correlation-of-responses.shtml# ?

Re: Correlation in Matched Pairs Platform

bbenny7 — Thu, 21 Nov 2024 14:39:47 GMT

Hi @Victor_G and @jthi ,

Thanks for you reply!

Is there any requirement on the correlation in order for the analysis to be valid? Does it have to be close to 1 as the matched pairs is used when the variable are dependent?

Re: Correlation in Matched Pairs Platform

MRB3855 — Thu, 21 Nov 2024 14:53:12 GMT

Hi @bbenny7 : No, there is no such requirement on the correlation (it is what it is).

Re: Correlation in Matched Pairs Platform

kasias — Wed, 27 Nov 2024 23:20:18 GMT

I also have the same question this week. That link is helpful for visual but doesn't give an equation for the matched pair correlation number.

It also seems to imply that the matched pairs correlation number should be related to the Rsq of a linear regression but when I compare the two on my data, they are very different. For example a dataset with poor Rsq (1 data point not following linear trend) still has a strong matched pair correlation #.

Anywhere suggestions where to look for the details on the equation? Thanks!!

Re: Correlation in Matched Pairs Platform

Victor_G — Thu, 28 Nov 2024 07:51:31 GMT

Hi @kasias,

R² (coefficient of determination) and R (correlation coefficient) are two different things, evaluating different aspects with different equations.

R² relates to the proportion of explained variance by a model, and the equation can be found here : Statistical Details for the Summary of Fit Report
R relates to the strength of the linear relationships between two variables : Multivariate Platform Options

Using the same Therm.jmp dataset as in the example or here : Example of Comparing Matched Pairs, I can find the same correlation coefficient than in the Matched Pairs analysis platform between the two responses with the Multivariate platform, estimating correlations in a row-wise manner :

So the correlation coefficient used in the Matched Pairs analysis is the Pearson Product-Moment Correlation.

Hope this answer will clear any doubts,

Re: Correlation in Matched Pairs Platform

kasias — Thu, 28 Nov 2024 23:11:04 GMT

oh great! that's what I was looking for. Thank you!!