The seventh Advanced Study Institute (ASI) on Techniques and Concepts of High Energy Physics was held for the second time at the Club St. Croix, in St. Croix, U.S. Virgin Islands. The ASI brought together a total of 75 participants, from 19 countries. The primary support for the meeting was again provided by the Scientific Affairs Division of NATO. The ASI was cosponsored by the U.S. Department of Energy, by Fermilab, by the National Science Foundation, and by the University of Rochester. A special contribution from the Oliver S. and Jennie R. Donaldson Charitable Trust provided an important degree of flexibility, as well as support for worthy students from developing countries. As in the case of the previous ASIs, the scientific program was designed for advanced graduate students and recent PhD recipients in experimental particle physics. The present volume of lectures should complement the material published in the first six ASIs, and prove to be of value to a wider audience of physicists.