Assessment & Research

Rapid generation of balanced trial distributions for discrimination learning procedures: a technical note.

Gerard et al. (2014) · Journal of the experimental analysis of behavior 2014
★ The Verdict

Use these free algorithms to instantly generate balanced trial sequences that block position or recent-outcome biases in your next discrimination study.

✓ Read this if BCBAs who run discrimination probes or matching-to-sample tasks in clinic or lab.
✗ Skip if Practitioners who only run naturalistic teaching without trial-by-trial data.

01Research in Context

01

What this study did

McGonigle et al. (2014) wrote a short how-to note. They give free computer code that spits out trial lists for any two-choice discrimination task.

The lists keep the left and right sides even. They also stop long runs of wins or losses that can sway choices.

02

What they found

The authors did not run new data. They simply show the code works and is ready to download.

03

How this fits with other research

Guilhardi et al. (2017) took the same idea into a classroom. Kids with autism liked lessons that mixed unknown and known trials more than big blocks of one kind.

Silverman et al. (1994) also cared about clean measurement. Their drug-disc task used point fines to curb random guesses, just like J et al. use balanced order to curb position guesses.

Blough (1980) warned that accuracy scores can lie if hidden biases steer the learner. The new code answers that warning by removing two big biases before the first trial starts.

04

Why it matters

Next time you set up a matching-to-sample or conditional-discrimination probe, paste the code into Excel. In five seconds you get a list that protects your data from side bias and win-streak bias. No extra math, no grant money, just cleaner sessions on Monday morning.

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→ Action — try this Monday

Open the paper, copy the Excel macro, and create today’s trial list that keeps left-right and win-loss counts even.

02At a glance

Intervention
not applicable
Design
methodology paper
Finding
not reported

03Original abstract

We describe novel computer algorithms for rapid, sometimes virtually instantaneous generation of trial sequences needed to instrument many behavioral research procedures. Implemented on typical desktop or laptop computers, the algorithms impose constraints to forestall development of undesired stimulus control by position, recent trial outcomes, and other variables that could impede simple and conditional discrimination learning. They yield trial-by-trial lists of sequences that can serve (1) as inputs to procedure control software or (2) in generating templates for constructing sessions for implementation by hand or machine.

Journal of the experimental analysis of behavior, 2014 · doi:10.1002/jeab.58