In statistics,

*homogeneity*and its opposite,*heterogeneity*, arise in describing the properties of a dataset, or several datasets. They relate to the validity of the often convenient assumption that the statistical properties of any one part of an overall dataset are the same as any other part. In*meta*-*analysis*, which combines the data from several studies,*homogeneity*measures the differences or similarities between the several studies (see also*Study**heterogeneity*).*Homogeneity*can be studied to several degrees of complexity. For example, considerations of homoscedasticity examine how much the variability of data-values changes throughout a dataset.