Record linkage, and its associated statistical problems, is a special case of a larger area of concern. This area makes use of various mathematical and statistical techniques to study the problems involved in the classification of observed phenomenon. Discriminant analysis, discrete discriminant analysis, pattern recondition, cluster analysis and mathematical taxonomy are some of the specific fields which study various aspect of the classification problem. While record linkage contains its own specific set of problems it also has a great deal in common with these other fields.