On the effectiveness of including meaningful pictures in the formation of equivalence classes
Slip a meaningful picture into the middle node of your equivalence sets to triple class-formation success.
01Research in Context
What this study did
The team ran three lab experiments with college students.
They taught four-member equivalence classes.
Some sets used only abstract shapes.
Other sets slipped a meaningful picture (like a dog or shoe) into the middle.
They tracked how many students formed the classes.
What they found
With only shapes, class formation stayed low—about 7 to 33 percent.
Adding a meaningful picture in the middle node jumped success to 50–93 percent.
Pictures at the ends helped less than pictures in the middle.
How this fits with other research
Rodríguez‐Valverde et al. (2021) used the same equivalence training but added shock avoidance.
Both studies show the classes form best when you tweak the nodes—pictures here, avoidance there.
Becerra et al. (2021) also used photos, yet with preschoolers with autism and for physical activity, not equivalence.
Together the three papers say: pictures boost learning across ages and goals, but you must match the photo to the skill you want.
Why it matters
If you run stimulus-equivalence lessons, drop a familiar picture into the middle spot.
One simple swap can triple how many learners master the class.
Try it next time you teach coin names, sight words, or category sorts.
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02At a glance
03Original abstract
In three experiments, 165 adult participants were trained on 12 baseline conditional discriminations and tested for the formation of three 5-member equivalence classes (A➔B➔C➔D➔E). All experiments included two reference groups; the abstract (ABS) group was trained with all abstract stimuli and the picture (PIC) group with C-stimuli as meaningful pictorial stimuli but A, B, D, and E stimuli as abstract shapes. In Experiment 1, the color of the meaningful stimuli was manipulated. In the ABS, PIC, and black-and-white groups, 33.3%, 80%, and 93.3% formed equivalence classes, respectively. In Experiment 2, participants were exposed to a test block with and without trials that included C stimuli. For the groups with and without C trials in the test, 93.3% and 86.7% formed equivalence classes, respectively, compared to 20% in the ABS group. In Experiment 3, the number of meaningful pictures and their location in stimulus classes were manipulated. One group was trained with 3 pictures (C1/B2/D3, the 3-PIC) while the other groups had 2 pictures (C1/B2 and C1/D3, the 2-PIC). In the second test block for the ABS and PIC groups, 6.7% and 86% of the participants formed equivalence classes, respectively. For the 3-PIC and the 2-PIC groups, 66.7% and 50% of the participants formed equivalence classes, respectively. Results suggest that the effects of meaningful stimuli in equivalence classes (a) cannot be attributed to the use of colorful stimuli in previous studies, (b) occur during training and are not dependent on the presence of meaningful stimuli at test, and (c) are sensitive to stimulus location.
Journal of the Experimental Analysis of Behavior, 2020 · doi:10.1002/jeab.579