Analysis of rule interestingness measures with respect to their properties is an important research area helping to identify groups of measures that are truly meaningful. In this article, we analyze property Ex1, of preservation of extremes, in a group of confirmation measures. We consider normalization as a mean to transform them so that they would obtain property Ex1 and we introduce three alternative approaches to the problem: an approach inspired by Nicod, Bayesian, and likelihoodist approach. We analyze the results of the normalizations of seven measures with respect to property Ex1 and show which approaches lead to the desirable results. Moreover, we extend the group of ordinally