Mental hospital patients in a motivating ward environment were using the available reinforcers less than was desired. A procedure for increasing the frequency of using reinforcers was developed: all patients were required to engage in the reinforcing event each time it was available but the duration of this required participation was limited so that the event was merely sampled. The effect of this required sampling was experimentally evaluated for three different reinforcers: going for a walk, watching a movie, and attending a music session. More patients used each of the three reinforcers and to a greater extent when the sampling procedure was used. Participation was increased even for those patients who had already been using the reinforcers, demonstrating that the technique did more than provide simple familiarization. Some familiarization was involved since the participation was slightly increased even after the sampling procedure was discontinued. The technique appears to be especially applicable when reinforcers are being delivered infrequently.