Confidence interval calculation on performance

Vorty

Hello,

I see that for many classification performance metric, RapidMiner provides an estimation which I interpret as an interval of confidence around the value provided. However I have failed to find the exact calculation that is performed, in particular for the kappa value.

To be clear, my question seems similar to the one of @taghaddo from last December (see post there: https://community.rapidminer.com/discussion/54694/error-range-of-classifier), which as far as I can tell, hadn't been answered to. Would anyone be able to clarify this point? Maybe by posting a snippet of the actual source code for that calculation as it seems to be sometimes done (e.g. for the kappa calculation there https://community.rapidminer.com/discussion/54909/regarding-kappa-value-in-cross-validation)?

Many thanks,

François

lionelderkrikor

Hi François,

It is because RapidMiner is using, in this particular case, a Cross Validation (See the Help section of this operator).
With this technique, RM is training and testing k models (according to the number of folds you set)
Thus it obtains k performances. Then RM calculates the average and the standard deviation of this k performances.
So the displayed values are  : mean +/- standard deviation

Regards,

Lionel