When things are not the same: A review of research into relations of difference
ABA has rich literature on sameness matching but almost none on teaching ‘difference’ relations—start probing oddity and distinction frames in your conditional-discrimination programs.
01Research in Context
What this study did
Ming et al. (2017) read every ABA paper they could find on conditional-discrimination training.
They hunted for studies that taught learners to pick the item that is DIFFERENT or ODD.
The team found almost none, so they wrote a roadmap for future research and teaching.
What they found
The field has piles of data on sameness matching: same shape, same color, same name.
Almost no one tests whether learners can select the one item that does NOT belong.
The gap matters because oddity and distinction skills underlie sorting, safety, and social cues.
How this fits with other research
Dowdy et al. (2021) show meta-analysis is now common in ABA, yet Ming et al. had too few difference studies to meta-analyze.
Hempkin et al. (2024) also map a thin evidence base, but in deictic relations (I-you, here-there); both reviews cry out for more work on complex relational frames.
Facon et al. (2011) and Flapper et al. (2013) warn that mean-only matching hides real group differences; Ming et al. extend this caution to teaching—if we only train identity matching we may miss whether learners truly notice what is NOT the same.
Why it matters
Next time you run a conditional-discrimination program, add one oddity trial set.
Ask the learner to hand you the picture that is NOT like the others.
Track the data; you will help close the research gap Ming et al. exposed and build a skill your clients will use every day.
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02At a glance
03Original abstract
Responding to stimuli as same and different can be considered a critical component of a variety of language and academic repertoires. Whereas responding to "sameness" and generalized identity matching (i.e., coordination) have been studied extensively, there appears to be a significant gap in behavior analytic research and educational programs with regard to nonmatching relations or relations of difference. We review research on difference relations from a variety of domains, including comparative psychology, as well as experimental, and translational behavior analysis. We examine a range of studies, including research on the perception of difference and oddity responding, as well as investigations on establishing relational frames of distinction. We present suggestions for future research and describe potential methods for teaching skills related to relations of difference.
Journal of Applied Behavior Analysis, 2017 · doi:10.1002/jaba.367