ABA Fundamentals

Training sequence effects on emergent conditional discriminations: Replication and extension to selection‐based training

Cox et al. (2021) · Journal of the Experimental Analysis of Behavior 2021
★ The Verdict

Teach tacts before intraverbals to make new conditional discriminations emerge faster and stronger.

✓ Read this if BCBAs building stimulus-equivalence classes with teens or adults.
✗ Skip if Clinicians focused only on compliance or listener-based programs.

01Research in Context

01

What this study did

Cox’s team asked a simple question. Does the order of two lessons matter?

They taught neurotypical adults to match pictures to printed words. Half learned tact first, then intraverbal. The other half got the reverse order.

The study used single-case probes to watch new relations pop out without extra teaching.

02

What they found

Tact-first won. Accuracy climbed higher, more new relations emerged, and answers came faster.

The reverse order still worked, but it took longer and gave weaker results.

03

How this fits with other research

Spackman et al. (2023) saw the same pattern in math. A set order—virtual before abstract—helped kids compute better. Both studies show that sequence is a variable you can measure and tweak.

Flores et al. (2025) reviewed high-probability sequences. They found that keeping reinforcers steady across steps boosts compliance. Cox adds that steady order also sharpens new learning, not just compliance.

Roper (1978) framed stimulus control as learning what predicts what. Cox’s data fit that frame: tact-first makes the picture-word link a clearer predictor, so the rest of the network forms faster.

04

Why it matters

If you run equivalence-based instruction, start with tacts. Call the picture “apple,” then ask, “What do you eat?” The tact primes the stimulus class and saves you trials later. One small flip can cut teaching time and give you more emergent relations for free.

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Run the first block as pure tact trials, then switch to intraverbal probes; track how many new relations pop up without direct training.

02At a glance

Intervention
stimulus equivalence training
Design
single case other
Population
neurotypical
Finding
positive
Magnitude
medium

03Original abstract

We examined the replicability and generality of a previously reported training sequence effect on emergent conditional discriminations in the intraverbal naming task. In Experiment 1, a tact-intraverbal (TI) group learned first to vocally label 6 visual patterns and then to intraverbally relate pairs of verbal labels, whereas an intraverbal-tact (IT) group received the same training in the opposite sequence. Emergent conditional discriminations among pattern stimuli were assessed in match-to-sample (MTS) format. Experiment 2 was identical, except vocal tact and intraverbal training were replaced with selection-based training in which the verbal labels were text stimuli. Compared to the IT sequence, the TI sequence resulted in greater mean accuracy at test (Experiment 1), higher yields (Experiment 2), and shorter reaction times (Experiment 2). Experiment 2 data suggested the TI group's performance might be less dependent on intact intraverbal relations relative to the IT group, but related to participants' reports of visualization during intraverbal training. The results suggest the sequence effect is replicable and occurs in experimental preparations commonly used to study derived stimulus relations. They also provide novel support for the hypothesis that participant behavior during training alters sources of stimulus control available at test.

Journal of the Experimental Analysis of Behavior, 2021 · doi:10.1002/jeab.713