The 'corrected' correlation for the inputs you gave is:


              

Please see the 'Explanation' tab for my health warning about this 'correction'.

This is ancient psychometrics but still of some use. For more information, see:

https://www.psyctc.org/psyctc/glossary2/attenuation-by-unreliability-of-measurement/

The formula is simple:

$$correctedR = \frac{obsR}{\sqrt{rel_{x} * rel_{y}}}$$

The short summary is that unreliability in the measurement of both variables involved in a correlation always reduces the observed correlation between the variables from what it would have been had the variables been measured with no unreliability (which is essentially impossible for any self-report measures and pretty much any measures used in our fields.)

I am putting 'scare quotes' round 'corrected' throughout this app because I think it's important to be very cautious about this 'correction' as it can return a correlation above 1.0 where you have a reasonable observed correlation and low reliabilities and as for any observed correlation, the lower your reliabilities the higher the 'corrected' correlation which feels uncomfortable to me for all I see the logic!

App created 13.x.24 by Chris Evans PSYCTC.org

Last updated 13.x.24.

Licenced under a Creative Commons, Attribution Licence-ShareAlike Please respect that and put an acknowledgement and link back to here if re-using anything from here.

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