A method for interrogating objects to identified over a communication medium utilizes objects that include a counter. The objects provide predetermined responses indicative of object identification numbers. Interrogation signals operate to interrogate a signal digit from the objects. Incomplete identification numbers are recorded and retrieved whenever two or more predetermined responses are received from the objects. A signal is sent to the objects to cause the objects to selectively add a number to their respective counter. The number is determined by each object and is dependent upon one or more previous responses of the object to interrogation signals. A signal is sent to the objects to cause the objects to selectively subtract a number from their respective counter. The number is determined by each object and is dependent upon one or more previous responses of the object top the interrogation signals. Complete identification numbers are recorded as they determined.