1. A system for classifying objects using a computer, the system comprising: an arrangement for receiving input data corresponding to identified properties of objects to be classified; an arrangement for formulating a query to identify objects having properties of interest, wherein the arrangement for formulating a query takes into account: properties that best define the query, wherein the properties that best define the query constitute a signature characteristic of an object collection that is know to belong to a particular class of interest, and further wherein the properties constituting a signature characteristic are determined utilizing an expression that best defines the object collection; and a desired form of output, wherein the query is manipulated to produce different forms of output based on the desired form of output; an arrangement for selecting properties of the objects to compare with object properties included in the query; an arrangement for determining if an object belongs in the query based on the selected properties; and an arrangement for obtaining a result yielded by the arrangement for determining if the object belongs in the query; wherein the system utilizes a processor to perform the classification.