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GA driven attribute selection according to Positive predictive value
Guru
In my case I am interested only in POSITIVE PREDICTIVE VALUE.
The problem is when I am selecting attributes - GA selects only the case with a single correctly classified example - and thus PPV = 100 %. This is of course of a very little reliability.
Could anyone help me which performance evaluator will fit my needs?
Thank you in advance for any help.
The problem is when I am selecting attributes - GA selects only the case with a single correctly classified example - and thus PPV = 100 %. This is of course of a very little reliability.
Could anyone help me which performance evaluator will fit my needs?
Thank you in advance for any help.
0
Answers
sorry, but I'm a bit confused. What exactly are you going to do? Which operator do you use?
Greetings,
Sebastian
I have binominal classification problem and what I am interested in is to maximize positive predictive value (PPV) . Therefore lets say I got these confusion matrices: accuracy: 74.84%
PPV: 57.46 %
This is quite good as the PPV is of 57.46 %
Lat have a look at this example: accuracy: 74.25%
PPV: 100.0 %
Here the PPV is 100 % (i.e. the perfect solution from the point of PPV view and the first is considered to be better)
Unfortunately - one sample positively classified is only of a little significance. There is high probability that when deployed on validation data the results will be very bad.
Results on a validation example set is 1) PPV: 55.9% 2) PPV: 0.0 % (two misclassified samples).
And here is my question - is there any solution how to objectively compare these two results?
Thanks in advance.
hmm, there is actually always a risk in concentrating on precision alone. Beside taking other measures into account, be it by a combination like f-measure, be it by weighting or be it by multi-objective optimization schemes (which is all possible within RapidMiner), I am afraid there is no general solution for a objective comparison.
Cheers,
Ingo