The Personal Activity Location Measurement System (PALMS) researchers at UCSD have created a web-based processing system for location (GPS) and physical activity (accelerometer) data. We will collect data on a pilot sample of 40 Hispanic persons to a) test the validity of PALMS assessments of transportation modes, and activity in different locations against an objective record of activities derived from images collected by Vicon Revue; b) compare PALMS assessments of transportation modes and activity locations to other self-report measures and interview measures; c) assess the construct validity of PALMS-based activity assessment.