Duration and rate of reinforcement as determinants of concurrent responding.

The team ran two pigeons on two VI schedules side-by-side. They changed how long each schedule stayed in force before switching to the next one.

Birds first lived with one schedule for many sessions. Later the schedule swapped every few minutes. The goal was to see if response rates still matched the true amount of food earned.

When the same schedule stayed on for days, the birds' pecking lined up perfectly with the food ratio. Quick schedule hops broke that match.

In other words, matching only showed up after long, stable exposure. Rapid changes made behavior look off-balance.

Kohlenberg (1973) also showed that timing matters. That study kept the signal on for the whole component; brief flashes killed observing. Both papers say the same thing: give the learner time to feel the contingency.

Glover et al. (1976) found that richer food made pigeons pause longer after each reinforcer. V et al. add that you must wait through those pauses across many sessions before you judge if matching has emerged.

Last et al. (1984) later showed that sensitivity keeps drifting even within one session. Pair that with V's work and you see a trend: early data can mislead; let the condition cook.

If you run concurrent schedules for choice or preference assessments, stay put. Switching too fast can make it look like the client does not match reinforcement, when they simply have not felt the difference yet. Let each condition run for several stable sessions before you move on.