The long range goals of this project are to develop a complete Skinfold Caliper System for the accurate assessment of total and segmental body fat in young and adolescent populations. The prototype developed in Phase I has features like digital display, online data storage, and a semi-automated, interactive control system designed to facilitate ease of use and to minimize observer error. Automated controls will compensate for differences in skinfold compressibility attributable to hydration, site of measurement, and to individual tissue variations. The Phase II clinical research goal will be to determine the equations necessary to predict the time course of skinfold compressibility in various young and adolescent groups and to refine and modify the Phase I instrument and make it ready for marketing in Phase III. These equations will provide the basis for an automation feature of critical importance in work with these populations; i.e. accurate and reliable skinfold reading obtainable with a much briefer standard duration of skin compression. These various features define a useful, competitively priced, and widely marketable tool for monitoring a clinically important aspect of various groups like obese, athletes, and individuals with various health disorders. A strong market for the fully developed system is anticipated in a wide variety of medical and research cottince. Phase II engineering refinements will bring the cost within reach.