The Bristol Observatory

              Incorporated in 1997 by John A. Pandiani, Ph.D., Sociologist 

                                             and Steven M. Banks, Ph.D., Mathematician

Probabilistic Population Estimation

United States Patent 

On October 22, 2002, the United States Patent and Trademark Office assigned patent #6,470,298 to the Bristol Observatory for the 

"Apparatus and method for probabilistic population size and overlap determination"

Abstract

"The invention is an apparatus and method for probabilistic determination of population size and population overlap in data containing records on the unique entities without unique identifiers for the unique entities and having at least one common type of information with a known distribution of finite expectation.  A computer determines population size by decomposing probabilistic calculations which include calculating a first probabilistic number of unique entities needed to satisfy a first value of the information with the known distribution, successively calculating a probabilistic incremental number of unique entities needed for a previous value of the information with the known distribution to increase to a subsequent value of the information with the known distribution , until the probabilistic number of unique entities needed to increase to a predetermined value of the information with the known distribution is calculated and summing the first probabilistic number of unique entities and the probabilistic incremental numbers of unique entities.  The computer determines population overlap of unique entities between first and second data sets by subtracting and probabilistic incremental number of unique entities needed for a larger total number of values of the information with the known distribution from either of the first and second data sets to increase to a total number of values of the information with the known distribution in the combined data set from a smaller of the population size of the first and second data sets."

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