I suppose one solution to loose pieces is to do much like the library does with its books. Having worked in one and seen the effectiveness of the system I ca nt see why it would not work. Similar systems are in place in many stores, etc .. using variations on the theme. The main idea being that the objects have a device in them that the scanner picks up if the device has not been deactivated prior to passing through the scanner. I have no idea of the costs involved ho wever if loss of the objects is a problem and costly over time a detection syst em may be cost effective. On the other hand have you done any exhibit studies to observe what is going on . Visitor studies methodology might tell you a lot. Anyway just some comments ... JIM Jim Ellis Office of International Studies and Programs 123 Tigert Hall Telephone: (904) 392-6356 (NEW #) UNIVERSITY OF FLORIDA BITNET: JELLIS@NERVM GAINESVILLE, FLORIDA 32611 INTERNET: [log in to unmask]