Nodality effects during equivalence class formation: An extension to sight-word reading and concept development.
Teach sight-word equivalence classes in nodal order: symmetry first, one-node next, two-node last.
01Research in Context
What this study did
Three students with intellectual disabilities learned sight-word equivalence classes.
Each child got single-sample/four-comparison conditional discrimination training.
The team tracked how fast symmetry, one-node, and two-node relations appeared.
What they found
Symmetry relations popped out first for every student.
One-node transitivity came next.
Two-node transitivity showed up last, proving the nodality effect.
How this fits with other research
Christian et al. (1997) extends this pattern to college adults and adds a twist: pretraining with extra nodes makes new classes form faster.
Bailey (2008) looks like a contradiction—pigeons got symmetry only with successive matching—but the clash fades when you see the species and procedure swap.
Fienup et al. (2017) keeps the same equivalence training game but tweaks mastery criteria instead of nodal distance, giving you another dial to turn.
Why it matters
Expect easier relations to emerge first and plan your teaching sequence that way.
Start with symmetry drills, then add one-node, then two-node to keep success high and frustration low.
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02At a glance
03Original abstract
Three students with moderate disabilities were taught to read and match-to-sample sight words comprising stimulus sets based upon the four food groups. We taught students conditional discriminations within four four-member sets using a single-sample/four-comparison procedure. Students were taught A-B, B-C, and C-D conditional discriminations for each of the four potential stimulus classes. Subsequent probes tested for relations based upon symmetry and one-node and two-node transitivity. The performances for all students indicated that symmetric relations emerged before one-node transitive relations, and that one-node transitive relations emerged before two-node transitive relations. These results are consistent with a pattern of responding, referred to as a "nodality effect," in which relations with fewer nodes are demonstrated prior to the demonstration of relations with a greater number of nodes. These results extend this area of research to sight-word reading for students with moderate disabilities.
Journal of applied behavior analysis, 1994 · doi:10.1901/jaba.1994.27-673