1. A method of normalizing a first field in a structured relational database, wherein the structured relational database has a plurality of records, the method comprising the steps: a) identifying a candidate record from a set of records taken from the plurality of records, each of the records in the set of records comprising at least the first field; and b) for one or more other records in the set of records, i) generating a similarity weight corresponding to the similarity of a candidate value in the first field of the candidate record to a corresponding value in the first field of the other record, the similarity weight reflecting one or more of the following: the similarities of the candidate value and the corresponding value; the similarities of values in one or more other fields of the candidate record to respective values in the corresponding one or more other fields of the other record; and the similarities of values in one or more fields of records that are related to the candidate record according to one or more relationships in the structured relational database to respective values in the corresponding one or more fields in records that are related to the other record according to the same one or more relationships; and ii) comparing the similarity weight against an acceptable threshold value and if the similarity weight is at least equal to the acceptable threshold value, reconciling the candidate value in the candidate record identified in step (a) and the value in the same field of the other record.