Speed contingencies, number of stimulus presentations, and the nodality effect in equivalence class formation.
Speed contingencies push college students to respond faster during equivalence training but cost a little accuracy.
01Research in Context
What this study did
College students learned matching-to-sample tasks to form equivalence classes.
Some trials paid extra if the student picked the answer quickly.
The researchers varied how many times each picture appeared to see how speed pay changed learning.
What they found
Speed money made students click faster but they made more mistakes.
The old idea that harder “nodal” steps always slow learning did not hold once speed pay was added.
Results were mixed: faster responding, slightly weaker equivalence.
How this fits with other research
Frampton et al. (2025) later got 90 % accuracy in one session by using cover-copy-compare and a graphic organizer instead of speed pay.
Sigurðardóttir et al. (2012) also saw near-perfect emergence with no speed push, showing strong classes form when you remove the hurry rule.
These studies do not truly clash; Imam (2001) shows what happens when you add a speed contingency, while the later papers show cleaner learning without it.
Why it matters
If you run equivalence lessons, skip speed rewards unless the goal is fluency after mastery. Use graphic organizers or plain matching first to lock in accurate classes, then add speed later for maintenance.
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02At a glance
03Original abstract
Two experiments compared performances on conditional discrimination tasks using single-participant designs with and without speed contingencies. Experiment 1 was a systematic replication of Spencer and Chase (1996). Experiment 2 presented equal numbers of training and testing trials. In each experiment, 2 female undergraduates participated. Each formed three five-member and three seven-member equivalence classes in Experiments 1 and 2, respectively. Response speed was an inverse function of nodal number and relational type in Experiment 1, but only of relational type (i.e., baseline, symmetry, transitivity, and equivalence) in Experiment 2, with and without the speed contingency. Accuracy tended to peak without the speed contingency in both experiments. Adding the speed contingency increased response speeds in both experiments, more so in Experiment 2 with a lower limited hold for I participant. The results of Experiment 2 cast doubt on previous reports of the nodality effect and on the notion of "relatedness" among class members, and they support a reinforcement-contingency, rather than a structural, account of equivalence class formation.
Journal of the experimental analysis of behavior, 2001 · doi:10.1901/jeab.2001.76-265