This learning module, which is intended for use in in-service training for vocational rehabilitation counselors, reviews the systematic methods available to measure and record client behavior. The first section covers procedures for making necessary calculations and keeping needed records with respect to behavioral events and their duration and interval. Also covered in the first section are procedures for use in time sampling, calculating a placheck (a term derived from the words "planned,""activity," and "check"), continuous recording, and developing permanent products. The second section deals with reliability for event and duration data and for interval and time sampling. Sample charts and graphs developed from various types of raw client observation data are presented. Five self-tests are also included. (MN)