Probability of Stimulus Equivalence as a Function of Class Size vs. Number of Classes

Abstract

Two experiments were conducted to study stimulus equivalence as a function of class size and number of classes. In the first experiment, equivalence was tested in 50 normal adult subjects following a linear series training structure. Subjects were successively assigned to either of 10 groups, exposed to a specific stimulus material. For subjects in which number of classes increased, up to six, B-stimuli served as pictures, while A-, and Cstimuli were Greek letters, and "equivalence" was tested in CA tests. The A-, B-, and C-stimuli were the same for all subjects in whom class members increased up to six, where D-, E-and Fstimuli were Greek letters. FOllowing AB, BC, CD, DE, and FE training , FA, EA, FB, FC, EB, DA, FD, EC, DB, and CA "equivalence" tests were run. In the second experiment, a manyto-one training structure was used to study equivalence as a function of increasing class size without increase number of nodes. The results indicate that the probability of equivalence decreased more as function the number of nodes than as a function of number of classes. Reaction times, particularly to the comparison stimuli, generally increased initially during tests, possibly indicating precurrent problem solving behavior prior to the response to a comparison stimulus.

The Effects of Different Training Structures in the Establishment of Conditional Discriminations and Subsequent Performance on Tests for Stimulus Equivalence

“…The reaction time was longer with an increased number of nodes, that is, the reaction time was longer in the LS training structure with 4 members than with 3-members. This is in accordance with previous research (Arntzen & Holth, 2000b;Bentall, et al, 1999;Fields, Adams, Newman, & verhave, 1990), but not in accordance with Imam (2006).…”

“…In the test, the sample is suddenly related to more than one comparison stimulus, and the reaction time could then increase. For all training structures, the increase in reaction time from baseline to the tests for responding in accord with stimulus equivalence could indicate that stimulus equivalence emerges more gradually and that reaction times indicate some problem-solving behavior or precurrent behavior (Arntzen & Holth, 1997, 2000b. It is important to note that this precurrent response is not some sort of intervening variable (Arntzen, 2004).…”

“…However, the effects of the number of nodes can only be studied when using a linear series training structure, because increasing the number of members in each class does not influence the number of nodes in MTO or OTM. A number of studies have found nodal effects, i.e., stimulus equivalence outcome decrease and reaction time increase, to be a function of the number of nodes (e.g., Arntzen & Holth, 2000b;Bentall, Jones, & Dickins, 1999;Fields, Landon-Jimenez, Buffington, & Adams, 1995;Kennedy, 1991). On the other hand, some other findings contradict this when the number of trials is equal per nodal number (Imam, 2006).…”

Probability of Equivalence Formation: Familiar Stimuli and Training Sequence

“…, 2000;Randell & Remington, 1999;Roche, BarnesHolmes, Smeets, Barnes-Holmes, & McGeady, 2000;Sidman & Tailby, 1982) and in different modalities (e.g., Annett & Leslie, 1995;Belanich & Fields, 1999;Hayes, Tilley, & Hayes, 1988;O'Leary & Bush , 1996); it has been shown both in normal adults and children (e.g., Lipkins , Hayes, & Hayes, 1993;Pi lgrim, Chambers, & Galizio, 1995) and in persons with mental disabilities (e.g., Saunders & Spradlin, 1993). Some studies have shown that equivalence classes are not so easily formed as was first assumed, especially after a linear series training structure (Arntzen & Holth , 1997, 2000a, 2000b. The use of familiar stimulus material appears to affect the probability of equivalence outcome , as was shown in Haith and Arntzen (1998), where responding in accord with equivalence increased when the nodal stimulus was a nameable picture as opposed to a condition in which all stimuli were Greek letters.…”

“…The use of familiar stimulus material appears to affect the probability of equivalence outcome , as was shown in Haith and Arntzen (1998), where responding in accord with equivalence increased when the nodal stimulus was a nameable picture as opposed to a condition in which all stimuli were Greek letters. Furthermore, in another study (Arntzen & Holth, 2000b), the purpose was to investigate the likelihood that equivalence class formation would vary as a function of class size and number of classes. In Experiment 1, the equivalence outcome as a function of class size or class number was studied in a linear series training structure.…”