Introduction to Imprecise Probabilities

10.7 Scoring the conditional probability of the class

If the final aim is to approximate the conditional information of the class given the attributes instead of optimizing the accuracy, then a different measure should be used. If conditioned to the attributes, what we obtain is a precise probability for the probability of the class , then the usual score for each case is the logarithm of the likelihood score: , where is the true value of the class. This scored is added for the different cases in the test set. If instead of a single probability, , what we obtain is a credal set , then there is not an obvious way of generalizing this score. Here we propose to use the following one: Let the probability having maximum entropy in , then we use the logarithm of the likelihood score computed with ...