Pigeons were trained in two experiments that used the concurrent-chains procedure. These experiments sought to identify the variables controlling the preference of pigeons for a constant duration over a variable duration of exposure to an aperiodic, time-based, terminal-link schedule. The results indicated that two variables correlated with the…

Following from an earlier analysis by B. F. Skinner, the present article suggests that the verbal processes in science may usefully be viewed as following a three-stage progression. This progression starts with (a) identification of basic data, then moves to (b) description of relations among those data, and ultimately concludes with (c) the…

The present research used pigeons in a three-key operant chamber and varied procedural features pertaining to both initial and terminal links of concurrent chains. The initial links randomly alternated on the side keys during a session, while the terminal links always appeared on the center key. Both equal and unequal initial-link schedules were…

For over 40 years, much research has sought to mathematically describe the relation between operant choice responding and reinforcement. This quantitatively oriented research and the accompanying theoretical interpretation of the data are embedded in the broader context of general experimental psychology, which can at times be regrettably…