1) A schedule of intermittent reinforcement in which a single reinforcement is programmed by two schedules acting in succession without correlated stimuli. E.g., in tand FI 10 FR 5 a reinforcement occurs when 5 responses have been executed after a 10 minute interval has elapsed. In tand FRFI, a (usually) short interval must elapse after the completion of a ratio before a response is reinforced. It is often important to specify which of the two schedules composes the more substantial part of the schedule. This can be done by italicising the important member.

2) A compound schedule in which a reinforcer is produced by the successive completion of two or more component schedules, all of which operate during a single stimulus.