Patent Document ID: 7668843
Application ID: 11302989
Patent Flag: 1

Claim One:
1. A method for execution by one or more digital processors, the method for detecting whether a current record in a dataset of records is an anomalous record, comprising: defining a feature of the records in the dataset; calculating, by the one or more digital processors, a plurality of pairwise distances between a value of the feature in the current record and values of the feature in at least some of the records in the dataset, where each pairwise distance is either: (A) small for mismatches between the values when both of the values rarely occur in the dataset records or where the distance is large for mismatches between the values when both of the values commonly occur in the dataset records; or (B) large for mismatches between the values when both of the values rarely occur in the dataset records or where the distance is small when both of the values commonly occur in the dataset records; and in response to the plurality of distances d, producing a score for the current record; indicating that the current record is anomalous if the score meets a predetermined criterion; wherein the distances are responsive to the frequency Freq(v i ) of the value v i of the feature in the current record and to the frequency Freq(v j ) of the value v j of the feature in another of the records in the dataset; and calculating each of the pairwise distances d from a value v i of the feature in the current record and a value v j of the feature in the other of the dataset records according to the relation d ⁡ ( v i , v j ) = log ⁢ N Freq ⁡ ( v i ) * log ⁢ N Freq ⁡ ( v j ) where N represents a number of records in the dataset.