In empirical research, criteria must be selected to use in identifying a strong family so a set of characteristics common to them can be assembled. Despite general agreement on the characteristics of strong families, the criteria that are used in a research study to differentiate between a functional and a dysfunctional family will depend on the perspective of the researcher and what s/he considers to be the functions of a family, and how s/he defines success. For example, is the education of children a family function or not? Is it more important to children to grow up to be happy or economically self-sufficient, or are both essential? Researchers have operationalized the concept of a strong family in a number of ways.