The act of combining data from heterogeneous sources with the intent of extracting information that would not be available for any single source in isolation. An example is the combination of different satellite images to facilitate identification and tracking of objects. The term is also used to mean the combination of statistically heterogeneous samples to construct a new sample that can be regarded as having come from an unobserved joint distribution of interest that is the act of inferring a joint distribution when one has information only about the marginal distributions. See also record the linkage and copulas.