Scoring-Training feb 2014 | Page 10

Kolmogorov-Smirnov Curve Shows how strong is the difference between the distributions of the “Bad” and “Good” borrowers Kolmogorov-Smirnov curve shows the difference between the distribution of “Goods” and “Bads”. The maximum difference between “Goods” and “Bads” distribution known as a Kolmogorov-Smirnov value, that is often used together with Gini value to asses scorecard quality. This point is the maximal difference between the distribution of “Good” and “Bad” customers Kolmogorov-Smirnov values usually calculated not only for the dataset that was used to create scorecard (training set), but also for a separate out-of-sample validation dataset. Kolmogorov-Smirnov values for training and validation datasets should be close to each other. When several scorecards compared, preference is given to the one with the highest Kolmogorov-Smirnov value. Unacceptable Kolmogorov-Smirnov curves • Kolmogorov-Smirnov for training and validation subsets are not similar • Kolmogorov-Smirnov value is very small • Is not high enough • Curve shape is not smooth www.plug-n-score.com