Disputas: Justice Mensah

Justice Mensah's public defense of his thesis at the Ph.D programme in Behavior Analysis. Thesis title: The Role of Meaningful Stimuli in the Formation of Equivalence Classes

Trial Lecture

Monday April 8 2019, at 10:00

Title: to be announced

Public defense

The candidate will defend his thesis on April 8 2019 at 12:15

We ask the audience to take their seats in good time before the public defense commences.

Ordinary opponents

Leader of the public defence

Professor Ingunn Sandaker, OsloMet

Supervisor

  • Abstract

    The current thesis examined equivalence class formation as a function of meaningful stimuli.

    The first study explored yields of class formation as a result of having zero, one, two or three meaningful stimuli as C-stimuli in three 5-member equivalence classes (A-B-C-D-E). The results of the study showed that class formation yields are a function of the number of meaningful stimuli in to-be-formed classes.

    The second study examined the inclusion of meaningful stimuli on equivalence class formation in large classes (three 7-member equivalence classes (A-B-C-D-E-F-G)) by exposing participants to two main experimental condition: ABS (to-be-formed classes consisted of only abstract stimuli) and PIC (to-be-formed classes consisted of abstract stimuli with the D stimuli as meaningful stimuli). The results from Study 2 showed that class formation yields were higher for the PIC group relative to the ABS group. 

    In Study 3, three experiments examined the color of meaningful stimuli (Experiment 1), the inclusion or exclusion of meaningful stimuli in emergent relations test trials (Experiment 2), and the effect of the number and location of meaningful stimuli (Experiment 3) on three 5-member equivalence classes formation. The findings from Experiment 1 showed that equivalence class formation is a function of the meaningful stimuli included in a to-be-formed classes and not necessarily the meaningful stimulus plus its color. The findings from Experiment 2 showed that equivalence class formation enhancement by a meaningful stimulus is as a result of the inclusion of the meaningful stimulus during conditional discrimination training and not as a consequence of the mere inclusion of the meaningful stimulus in emergent relations testing. In Experiment 3, the results showed that equivalence class formation is a function of the number and location of meaningful stimuli in a to-be-formed class.

    Key Words: Meaningful stimuli, equivalence class formation, conditional discrimination, stimulus sorting, stimulus control, matching-to-sample, experiment-defined classes