Sensitivity and bias under conditions of equal and unequal academic task difficulty

We conducted an experimental analysis of children's relative problem-completion rates across two workstations under conditions of equal (Experiment 1) and unequal (Experiment 2) problem difficulty. Results were described using the generalized matching equation and were evaluated for degree of schedule versus stimulus control. Experiment 1 involved a symmetrical choice arrangement in which the children could earn points exchangeable for rewards contingent on correct math problem completion. Points were delivered according to signaled variable-interval schedules at each workstation. For 2 children, relative rates of problem completion appeared to have been controlled by the schedule requirements in effect and matched relative rates of reinforcement, with sensitivity values near 1 and bias values near 0. Experiment 2 involved increasing the difficulty of math problems at one of the workstations. Sensitivity values for all 3 participants were near 1, but a substantial increase in bias toward the easier math problems was observed. This bias was possibly associated with responding at the more difficult workstation coming under stimulus control rather than schedule control.     

Fluent Reading as the Improvement of Stimulus Control: Additive Effects of Performance-Based Interventions to Repeated Reading on Students' Reading and Error Rates

The impact of adding performance-based interventions to a skill-based intervention on oral reading fluency was examined with 3 elementary students identified as having difficulty with reading. Two performance-based interventions were combined with the skill-based intervention Repeated Reading (RR) to create the three instructional packages investigated. The packages included Repeated Readings (RR), Repeated Readings with Performance Feedback (RR/FB), and Repeated Readings with Performance Feedback and Contingent Reward (RR/FB/REW). Results suggested that Repeated Reading (RR) alone led to the greatest increase in reading fluency for participants with the highest reading rates and lowest error rates at baseline. In contrast, the participant who exhibited the lowest reading rate and highest error rate benefited the most when Repeated Readings was offered in conjunction with Performance Feedback (RR/FB) or Performance Feedback plus Contingent Reward (RR/FB/RW). Implications for blending skill- and performance-based interventions to develop stimulus control over fluent reading and future research directions are discussed.     

Assessment and prediction in an ecological system: Application of the general linear model to the response-class concept

This study investigated the extent to which observed frequencies of covarying responses could be utilized in the prediction of classroom behavior. Five behavior categories were observed daily over a 12-week period in the regular classroom settings of four fifth-grade and two fourth-grade male students. For each subject, stepwise regression analyses were conducted to determine which behaviors accounted for the largest proportions of variance in a single response category. The proportions of variance explained in the behavior categories of the subjects ranged from 8.9 to 75.4%. Further, response categories serving as predictor variables, as well as the number of predictor variables entered into the equations, differed across subjects. These results are discussed in terms of their implications for behavioral assessment and treatment application.     

Contingency and choice: The implications of matching theory for classroom instruction

This paper describes a mathematical account of behavior known as matching theory. Matching theory evolved out of basic operant research and assumes that individuals can engage in a variety of behaviors at any moment, but they choose one to the exclusion of others. According to the matching equation, choices in behavior match the relative amount of reinforcement provided for each alternative. Although the principles of matching theory have proven useful in developing novel treatment strategies, few data exist validating the matching equation in natural human environments. Recent applications of matching theory to children's classroom behavior are described, and the implications of matching theory for classroom management and effective teaching are discussed.     

What masks utrocular discrimination

Utrocular discrimination, the ability to judge which eye has received monocular stimulation, was studied under conditions designed to reduce the salience of the cue mediating this discrimination. In one series of experiments, these conditions involved reducing the likelihood of motor command signals, overwhelming the motor command centers, and triggering motor command signals for both eyes. Those results indicate that utrocular discrimination is not mediated by ocular movements or command signals. In a second series of experiments, a visual masking paradigrn was used. A monocular test grating appeared superimposed upon a background of binocular masking noise, which was presented either simultaneously with the target or at some interval preceding or following the target (asynchronous masking). When presented simultaneously, the binocular masking noise interfered with utrocular performance, but only when the noise contained spatial frequencies near the test frequency. Masking functions obtained under conditions of asynchronous masking indicated that the time course of the forward and backward masking changed with spatial frequency. Finally, a sustained masking pattern that was ineffective in reducing utrocular performance could be made effective by pulsing the mask simultaneously with the target. Taken together, these results implicate a transient response to the target onset as a critical factor in generating the cue for successful utrocular discrimination. This conclusion may account for the fact that utrocular discrimination falls off for normal observers as the spatial frequency of the target grating increases above 4 cycles/deg.     

The generalized matching law in elite sport competition: football play calling as operant choice

A mathematical model of operant choice, the generalized matching law was used to analyze play-calling data from the 2004 National Football League season. In all analyses, the relative ratio of passing to rushing plays was examined as a function of the relative ratio of reinforcement, defined as yards gained, from passing versus rushing. Different analyses focused on season-aggregate data for the league as a whole, game-by-game data for the league as a whole, and game-by-game data for individual teams. In all analyses except those for a few individual teams, the generalized matching law accounted for a majority of variance in play calling. The typical play-calling pattern reflected undermatching (suggesting imperfect sensitivity of play calling to yardage-gained reinforcers) and a bias for calling rushing plays. Bias was found to be a function of both the relative risk of turnovers and the relative variability in yards gained associated with passing versus rushing plays. The external validity of the matching analyses was supported by significant correlations between parameters of the generalized matching law and team success on offense and season winning percentage. These results illustrate the broad applicability of the generalized matching law to problems outside of the laboratory.     

Windows into nothingness: terror management, meaninglessness, and negative reactions to modern art

Why do people dislike art that they find meaningless? According to terror management theory, maintaining a basic meaningful view of reality is a key prerequisite for managing concerns about mortality. Therefore, mortality salience should decrease liking for apparently meaningless art, particularly among those predisposed to unambiguous knowledge. Accordingly, mortality salience diminished affection for modern art in Study 1, and this effect was shown in Study 2 to be specific to individuals with a high personal need for structure (PNS). In Studies 3 and 4, mortality salient high-PNS participants disliked modern art unless it was imbued with meaning, either by means of a title or a personal frame of reference induction. Discussion focused on the roles of meaninglessness, PNS, and art in terror management.