The relationship between differential stimulus relatedness and implicit measure effect sizes
FAST scores rise in lock-step with how tightly stimuli are related, giving BCBAs a fast, wire-free gauge of equivalence strength.
01Research in Context
What this study did
Cummins et al. (2018) asked adults without disabilities to learn picture pairs in a matching-to-sample lesson.
After training, the team ran a FAST test. FAST is a quick computer task that measures how strongly the pictures now 'belong' together.
The researchers wanted to know if FAST scores would grow in step with how related the pictures felt to the learner.
What they found
FAST effect sizes went up in a straight line as stimulus relatedness got stronger.
In plain words: the more the adults felt the pictures were connected, the bigger the FAST number grew.
This supports FAST as a yardstick for equivalence strength—bigger score, tighter class.
How this fits with other research
Haimson et al. (2009) saw the same learning process but used brain waves. They found ERP signals only changed after learners passed equivalence tests. Cummins shows you can skip the wires and still get a clean read with FAST.
Tantam et al. (1993) proved that once classes form, new functions can jump to untrained items. Cummins adds a ruler: FAST tells you how strongly that jump is likely to be.
O’Connor et al. (2020) moved the training to children with autism and still saw derived relations. Cummins’ FAST metric could give those teachers a quick gauge of how solid the child’s new links are.
Why it matters
You now have a five-minute, laptop-based tool that sizes up equivalence strength without quizzes or wires. Try running FAST after your next equivalence lesson. If the score is low, add more training or mix in new examples before moving on.
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02At a glance
03Original abstract
Implicit measures have been hypothesized to allow researchers to ascertain the existence and strength of relations between stimuli, often in the context of research on attitudes. However, little controlled behavioral research has focused on whether stimulus relations, and the degree of relatedness within such relations, are indexed by implicit measures. The current study examined this issue using a behavior-analytic implicit-style stimulus relation indexing procedure known as the Function Acquisition Speed Test (FAST). Using a matching-to-sample (MTS) procedure to train stimulus equivalence relations between nonsense syllables, the number of iterations of the procedure was varied across groups of participants, hence controlling stimulus relatedness in the resulting equivalence relations. Following final exposure to the MTS procedure, participants completed a FAST. Another group of participants was exposed to a FAST procedure with word pairs of known relatedness. Results showed that increasing relatedness resulted in a linear increase in FAST effect size. These results provide the first direct empirical support for a key process-level assumption of the implicit literature, and offer a behavior-analytic paradigm within which to understand these effects. These results also suggest that the FAST may be a viable procedure for the quantification of emergent stimulus relations in stimulus equivalence training.
Journal of the Experimental Analysis of Behavior, 2018 · doi:10.1002/jeab.437