Definition of homogeneous exposures

elements within a group under study that have the same characteristic(s), have the same expectation of loss, are very much alike with respect to the variable under consideration, and do not show significant differences through any given time periods. Homogeneity of exposure units is extremely important to the accuracy of the prediction of future losses based on historical loss experience. For example, if an actuary is going to predict the number of wood-frame houses likely to suffer a fire loss, the sample upon which the prediction is based should consist of wood-frame houses, not brick-frame houses.