Inductive Conformal Prediction: Theory and Application to Neural Networks

This chapter presented the Inductive Conformal Prediction (ICP) approach for producing confidence measures with predictions and described its application to Neural Networks. ICPs accompany each of their predictions with probabilistically valid measures of confidence. Furthermore, they do not need the relatively large amount of processing time spend by Transductive Conformal Predictors (TCPs) to perform their computations. In fact their computational efficiency is virtually the same with that of their underlying algorithms. The experimental results detailed in Section 5 and in (Papadopoulos et al., 2002a; Papadopoulos et al., 2002b; Papadopoulos et al., 2007) show that the accuracy of ICPs is comparable to that of traditional methods, while the confidence measures they produce are useful in practice. Of course, as a result of removing some examples from the training set to form the calibration set, they sometimes suffer a small, but usually negligible, loss of accuracy from their underlying algorithm. This is not the case, however, for large data sets, which contain enough training examples so that the removal of the calibration examples does not make any difference to the training of the algorithm.