Understanding the representativeness of the data is important in order to determine the generalizability of the results. Results from a study that is representative of the entire U.S. can be generalized to the entire U.S. If the study found that reading to children daily improves children’s test scores, then we can be confident that this finding applies to the average American child. Results from a study that is representative of a more narrow population cannot be generalized beyond that population. For example, results from a study of mothers applying for WIC in Ithaca cannot be generalized to all mothers in the state of New York.