Motivating Operations and Discriminative Stimuli: Distinguishable but Interactive Variables

Poling and colleagues wrote a think-piece, not an experiment.

They looked at how we talk about motivating operations (MOs) and discriminative stimuli (SDs).

The team asked: Do we really need tiny MO sub-types, or should we just watch how MOs and SDs work together in real time?

The paper says the old split between "conditioned MO" types just clutters our charts.

Instead, it offers one clean phrase: MO–SD interaction.

If you see a reinforcer suddenly gain or lose power, look at both the kid’s state (MO) and the cues in the room (SD) at the same moment.

Edwards et al. (2019) made the first move, telling us to drop the behavior- vs function-altering line.

Poling et al. (2020) keep that drop, but add the spotlight on moment-to-moment MO–SD mixing.

O'Reilly et al. (2008) showed the idea in action: a five-minute taste of a reinforcer cut problem behavior, proving an MO tweak can work without touching SDs.

King et al. (2025) flip the view, showing SD qualities of the same reinforcer can later steer resurgence.

Together the chain moves from old rule book → rethink → live demo → finer demo, each step sharpening how we spot why behavior flares or fades.

Next time a client’s motivation looks "random," pause and list two things: what the child just did or ate (MO) and what signals are in the room (SD).

Train staff to say "MO–SD interaction" in reports instead of piling on new CMO labels.

Cleaner notes, faster team talk, and you still keep all the predictive power.