Stimulus control and the response-reinforcement contingency.

Researchers worked with pigeons in a small lab chamber.

The birds had to wait a short time between pecks.

If they pecked too fast, no food came.

Colored lights told the birds when the timing rule was on.

The team asked: do the lights still control the birds’ pecks when a wait-time rule is added?

The colored lights kept full control.

Even with the wait rule, birds pecked only when the correct light was on.

Timing rules alone did not weaken stimulus control.

Haring (1985) extends this idea.

That study shows long pauses (>1 s) make external stimuli even stronger.

Together, the two papers say: timing rules do not hurt control, and longer waits can help it.

Schwartz et al. (1971) also extends the work.

They gave birds an extra key to peck while waiting.

That extra key acted like a toy timer and raised accurate waiting from 10 % to 75 %.

The 1969 paper shows control survives; the 1971 paper shows you can boost timing with a simple extra cue.

If you use DRL or IRT schedules with clients, check stimulus control directly.

Do not assume the timing rule will wash out your SD.

You can keep your current cues and still teach slower, spaced responses.