ABA Fundamentals

The logistics of choice.

Killeen (2015) · Journal of the experimental analysis of behavior 2015
★ The Verdict

The matching law is just logistic regression driven by the Law of Effect, not a separate behavioral law.

✓ Read this if BCBAs who teach choice or run concurrent-schedule assessments.
✗ Skip if Clinic staff who only do discrete-trial training.

01Research in Context

01

What this study did

Killeen (2015) wrote a theory paper. The author looked at the generalized matching law. He asked why choice ratios line up with reinforcer ratios.

He showed the math. The matching law is just logistic regression in disguise. The real driver is the old Law of Effect, not a special matching process.

02

What they found

The paper found no new numbers. It found a new view. Matching is not a separate law. It is a by-product of reinforcement history.

The Law of Effect does the work. Logistic regression captures it. The matching equation is only one way to write it down.

03

How this fits with other research

Nakamura et al. (1986) reviewed hundreds of pigeon sessions. They showed the matching law fits 91% of the variance. Killeen (2015) keeps the fit but changes the story.

Villarreal et al. (2019) gave us Bayesian tools to estimate matching parameters. Those same tools now fit the logistic view.

Caron (2024) fixed undefined log ratios with modern stats. His fixes work for both old matching and new logistic forms.

04

Why it matters

You can stop teaching matching as a magic rule. Teach it as reinforcement history filtered through logistic odds. When you graph choice data, fit a logistic curve first. If it fits, the Law of Effect already explains the pattern. Save the matching plot for staff who like straight lines on log paper.

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Try fitting a logistic curve to your next concurrent-schedule dataset before you draw the log-ratio plot.

02At a glance

Intervention
not applicable
Design
theoretical
Finding
not reported

03Original abstract

The generalized matching law (GML) is reconstructed as a logistic regression equation that privileges no particular value of the sensitivity parameter, a. That value will often approach 1 due to the feedback that drives switching that is intrinsic to most concurrent schedules. A model of that feedback reproduced some features of concurrent data. The GML is a law only in the strained sense that any equation that maps data is a law. The machine under the hood of matching is in all likelihood the very law that was displaced by the Matching Law. It is now time to return the Law of Effect to centrality in our science.

Journal of the experimental analysis of behavior, 2015 · doi:10.1002/jeab.156