Electronic article security system for store which uses intelligent security tags and transaction data

A method for monitoring a collection Of articles for shrinkage, each of the articles in the collection having a security tag attached thereto, the security tag including a resonant circuit for use in detecting the presence of the article by receiving an interrogation signal and returning a response signal, and an integrated circuit connected to the resonant circuit for storing article identification information and for outputting the article identification information with the response signal upon interrogation of the security tag by an interrogator of an electronic article security system, the method comprising the steps of:

• (a) recording article transactions, including article purchases, at one or more point-of-sale terminals, the transaction records including specific product identification information;
• (b) monitoring a detection zone with the interrogator for disturbances in the form of a response signal caused by the presence of a security tag within the zoned the interrogator outputting an interrogator output signal when a security tag is detected in the zoned each interrogator output signal including the article identification information stored in the integrated circuit, the, interrogator output signal being obtained at a location and time which is different than the location and time that the article transactions are recorded;
• (c) sending the transaction records and the interrogator output signals to one or more computers for storage therein;
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• (d) comparing in a computer the stored transaction records and the interrogator output signals, including the product and article identification information, and detecting any discrepancies which occur therebetween.