Patent ID: 8489617

Claim:
A computer implemented method of detecting and treating one or more field values as null field values in records of an electronic database, the computer implemented method comprising: selecting a field of the records; determining, using a programmed computer, a frequency for each field value of the field, the frequency comprising an amount of the records in which the field value of the field appears; calculating, using a programmed computer, a critical frequency for the field based on an ordered histogram of the frequency of each field value of the field, the critical frequency comprising a frequency at which a first point of a derivative of the ordered histogram decreases below a threshold; and treating, using a programmed computer, each field value of the field with a_frequency that is greater than the critical frequency of the field as a null field value and each field value of the field with a frequency that is less than the critical frequency of the field as a non-null field value.