Abstract
This experiment presents a manual-observing procedure as an inexpensive alternative for investigating stimulus control and establishing equivalence classes in a matching-to-sample task (MTS). To illustrate the procedure, we evaluated the effects of different MTS training structures on observing responses and equivalence class formation. Participants had to press a button below each covered sample and comparison stimuli to reveal the stimulus. Four participants were exposed to two different sequences of the many-to-one (MTO) and one-to-many (OTM) procedures, using the manual-observing procedure during training and testing. The results showed that the manual-observing procedure allowed participants to acquire conditional discriminations and form equivalence classes, suggesting that the use of manual-observing responses in an MTS procedure is a useful procedure to evaluate stimulus control in an MTS task.