Although shaping is a widely accepted operant-conditioning procedure for establishing new responses, technological problems involved in specifying and recording precise approximations to the target response have hindered experimental analysis of the shaping process. The present study used a computer-controlled system that allows relatively precise procedural specification by continuous tracking of a pigeon's head and reinforcing successively closer approximations to contact of the head with an arbitrary fixed spherical region of 3-cm diameter. The procedure was demonstrated to be effective, in that shaping of the target response occurred rapidly for each of the 3 birds in the study.
