1. A method comprising the steps of: receiving a sample volume of information requests originating at a network access device for processing in accordance with a request/response protocol; recording an indication of whether each information request of the sample volume was invoked by action of a network access device user or by a prior information request; examining the response to each received information request of the sample volume to identify its file type; storing an indication of the file type of the response to each received information request of the sample volume; applying an evaluation engine using at least one initial criterion to thereby establish an initial boundary between those information requests invoked by an action of a network access device user and those information requests invoked by a prior information request; classifying each information request of the sample volume as invoked by action of a network access device user or by a prior information request on the basis of whether or not the at least one criterion is satisfied; measuring a distance between a number of information requests classified as being invoked by the user and an actual number of information requests invoked by the user; measuring an overall ratio of information requests classified as being invoked by the user to an overall number of information requests before and after modifying the at least one initial criterion applied by the evaluation engine; and repeating the classifying and modifying steps so as to progress toward a one-to-one correspondence between a number of information requests classified as invoked by the user and the actual number of information requests invoked by the user.