Disputas: Laurilyn D. Jones

Laurilyn D. Jones will defend her thesis for the PhD in Behavior Analysis.

Laurilyn D. Jones will defend her thesis “Topographic Bias and Variability within Non‐Criterial Components of the Operant Class” for the PhD in Behavior Analysis.

Trial Lecture

September 26 2019 at 10:00

Title: To be announced

Public defense

The candidate will defend her thesis September 26 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 Per Holth, Oslo Metropolitan University


  • Abstract

    Topographic bias and behavioral variability are two fundamental characteristics of the operant class, and are present to some degree in all experimental analysis of behavior, whether measurable or not.  They represent the overlapping effects of multiple extra-experimental contingencies, often drawn from the organism’s biology and history, which interact with the programmed experimental contingencies. 

    All operant classes have both criterial and noncriterial dimensions, with the criterial ones being those that must occur in order for the programmed consequences to take place, and the noncriterial ones being all other behaviors and aspects of behaviors associated with each operant occurrence.  Bias and variability can affect both criterial and noncriterial aspects of the operant, but their effects are most often visible within the noncriterial ones. 

    The seven experiments with human participants reported in this thesis used a novel methodology, the revealed operant, that permits the measurement of noncriterial data, thus allowing for an in-depth analysis of both topographic bias and noncriterial variability effects on common behaviors such as drawing and typing.  Major findings include 1) an overall bias toward the center of the apparatus in use; 2) a bias toward movement of the hands across the horizontal plane in front of the torso, in particular a preference for moving the hand either right to left or near to far; 3) a bias toward efficiency of motion, even when the movements required were so small as to be almost indistinguishable in effort; 4) high levels of noncriterial variability even when stereotypy would have been equally reinforced, especially variability associated with performance errors; and 5) levels of variability correlated with certain measurements of bias, indicating that the two phenomena can interact under certain circumstances.  These findings have implications for current and future behavioral research, as well as for the theory of the operant as a motor program, and theories of automaticity and behavioral variability.

    Keywords: Topographic bias, bias, noncriterial variability, motor learning, kinesthetic bias, perceptual bias