Patent attributes
The similarity between a query set comprising query set tokens and a database set comprising database set tokens is determined by a similarity score. The database sets belong to a data collection set, which contains all database sets from which information may be retrieved. If the similarity score is greater than or equal to a user-defined threshold, the database set has information relevant to the query set. The similarity score is calculated with an inverse document frequency method (IDF) similarity measure independent of term frequency. The document frequency is based at least in part on the number of database sets in the data collection set and the number of database sets which contain at least one query set token. The length of the query set and the length of the database set are normalized.