Performance evaluation of learning algorithms - Mohak Shah
Performance evaluation of learning algorithms - Mohak Shah
Performance evaluation of learning algorithms - Mohak Shah
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ROC Analysis<br />
ROC Analysis is applicable to scoring rather<br />
than merely deterministic classifiers<br />
ROC graphs are insensitive to class imbalances<br />
(or skew) since they consider the TPR and FPR<br />
independently and do not take into account<br />
the class distribution. They, therefore, give very<br />
nice overall comparisons <strong>of</strong> two systems.<br />
However, practically speaking, ROC graphs<br />
ignore the skew which the performance<br />
measures <strong>of</strong> interest (pmi) usually takes into<br />
consideration. Therefore, at model selection<br />
time, it is wise to consider isometrics for pmi<br />
which are lines in the ROC space along which<br />
the same performance value is obtained for<br />
that pmi. Different skew ratios are represented<br />
by different isolines, making the selection <strong>of</strong><br />
the optimal operating point quite easy.<br />
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