1. A method comprising: defining a plurality of terms for use in conjunction with a study where the terms are stored according to a series of relations and the relations corresponding to the terms indicate an association from a term to at least one other of the plurality of terms; defining at least one group of terms taken from the plurality of terms and storing at least one group of terms, including the relations corresponding to each term; defining a further level of relations to be applied to the group of terms, the further level of relations defining inclusion and exclusion criteria; and providing a match term defined by the group of terms and querying a memory of data from the study to find occurrences of the match term as defined by the further level of relations.