Concurrent schedule responding as a function of body weight

Five pigeons pecked for food reinforcement on several concurrent schedules. Their body weights were varied from 80% to 110% of their free-feeding weights. A number of predictions of the equations proposed by Herrnstein (1970) were tested. As predicted, the relative rate of responding equalled the relative rate of reinforcement for all subjects, on all schedules, at all body weights. And, as predicted, the overall rates of responding on the components of a concurrent schedule were slower than the local rates of responding on the components of an identical multiple schedule. Contrary to prediction, the total rate of responding generated by the concurrent schedules did not increase with increases in the total rate of reinforcement they provided. And, contrary to prediction, the k parameter did not remain constant, and the R₀ parameter did not increase with increases in body weight. It was concluded that Herrnstein’s matching law and his interpretation of the m parameter are correct but that the interpretations of k and R₀ require further investigation.     

Exploring college students’ cognitive patterns during reasoning*

This research aimed to investigate the nature of cognitive processes when college students reason about evidence on global climate change (GCC). Twenty-six undergraduate students participated in this qualitative study, where they were interviewed to evaluate competing arguments on key issues related to GCC and discuss their own perspectives. Constant comparative analysis of data from think-aloud protocols and semi-structured interviews revealed three patterns of reasoning: minimum reasoning, constrained reasoning, and deliberative reasoning. Minimum reasoning demonstrated that participants predominantly favoured arguments which supported their own beliefs, with limited reasoning about the relative correctness of opposing arguments. Constrained reasoning showed participants’ emphasis on surface features of evidence on GCC rather than its scientific underpinnings. In contrast, deliberative reasoning involved more sophisticated cognitive efforts in coordinating evidence and claims, and a key characteristic of this pattern was in-depth statistical and causal reasoning. The current findings added to our understanding of college students’ reasoning processes when they are faced with controversial issues like GCC. This work contributed to current efforts in using cognitive research to inform science and environmental education, and laid a foundation for future endeavours in promoting scientific reasoning and argumentation in climate change education.     

Behavioral contrast as a function of component duration and baseline rate of reinforcement

Three experiments examined changes in size of multiple-schedule behavioral contrast with changes in an independent variable. Experiment 1 found that positive contrast generally increased with increases in component duration when pigeons pressed treadles. Experiments 2 and 3 found that positive and negative contrast generally increased with increases in the baseline rates of reinforcement when pigeons pecked keys. The experiments show that positive and negative contrast vary as similar functions of the same variables. Experiment 1 also suggests that these functions are different for different responses.     

Agreement among four models used for diagnosing learning disabilities

We compared the level of agreement among four models used to diagnose learning disabilities (LD), including the simple discrepancy, intraindividual, intellectual ability-achievement, and underachievement models. The sample included 170 clinic-referred university students. The simple discrepancy model diagnosed significantly more students with LD than the other three models. The highest degree of agreement occurred between the intraindividual and intellectual ability-achievement models (70%); the lowest level of agreement occurred between the simple discrepancy and underachievement models (48%). Finally, only two of the six comparisons among the four models demonstrated significant correlations. We conclude that even when discrepancy models diagnose similar numbers of students with LD, the same students are not diagnosed across different models.     

Quality of extension advice: a gendered case study from Ghana and Sri Lanka

Purpose: Women farmers have less access to extension services than male farmers, even though they make up almost half of the global agricultural workforce. Gender-focused international development programmes have focused on how ensuring women receive better access to advice. However, the quality of the technical advice and the service women receive in comparison to male farmers needs better understanding. Study design/methodology/approach: Five thousand interactions between male and female extension workers (‘plant doctors’) and farmers attending Plantwise plant clinics in Ghana and Sri Lanka are assessed for gender-based differences on quality of advice and service provided at clinics. Findings: The overall quality of technical advice given to male and female farmers at plant clinics in both countries did not differ. The quality of the advice given by male and female plant doctors for a specific pest/crop complex was different, and can be linked to results from the quality of service surveys that revealed women’s main negative feedback was the impracticality of advice. Practical implications: Whilst the advice given is technically sound, results highlight the importance of appropriate advice, according to farmer gender and crop grown. Theoretical implications: A greater focus on plant doctors using their knowledge about women’s role in agriculture would help to achieve more tailored advice. Originality/Value: This study leads the way in assessing the quality of the advice given according to gender. With large datasets, this research should help decision makers and future researchers to contemplate advice delivery according to gender.     

Within-session changes in responding during delayed matching-to-sample and discrimination procedures

Two experiments examined within-session changes in responding during discrimination procedures. In Experiment 1, rate of responding changed significantly within sessions during symbolic delayed matching-to-sample tasks when the delay between the stimulus and the choice period was short (1–5 sec), but not when it was long (8–12 sec). The percentage of responses that were correct did not change within sessions. In Experiment 2, response rates increased and then decreased within sessions during both S1 and S2 when successive discrimination procedures provided high, but not low, rates of reinforcement. Discrimination ratios sometimes increased within sessions. These results question two potential definitions of attention as explanations for within-session changes in response rates. They are more compatible with explanations based on concepts such as arousal, satiation, habituation, and interfering responses.     

Uncoupling the Articulation Between Girls' Education and Tradition in Tanzania

This article explores theoretical and historical problems associated with representations of gender and race in the Third World. Using a feminist cultural studies approach, the author examines representations associated with the concept of African tradition that have shaped colonial and post-colonial education policy for girls in Tanzania. Archival materials from missionary, colonial, and African sources reveal the multiple and often conflicting views of tradition conveyed through programmes intended to increase African girls' participation in school. The uses of tradition in colonial policy making are compared with its meanings in contemporary educational programmes for girls in an attempt to further feminist scholarship and action around the issue of girls' education.     

ADHD Coaching With College Students: Exploring the Processes Involved in Motivation and Goal Completion

College students with attention-deficit/hyperactivity disorder (ADHD) often experience increased academic difficulties, which can negatively impact graduation rates, employment, self-esteem, and mental health. ADHD coaching assists students with ADHD to reduce such difficulties. The present study evaluated the processes involved in ADHD coaching by examining undergraduate and graduate level students (n = 23) who attended individualized ADHD coaching sessions for 8 weeks. Specifically, the study examined the types of goals established, the use of weekly objectives (tasks to be completed), barriers to task completion, the use of incentives and consequences to increase motivation, and the role of task enjoyment and therapeutic benefit on task completion. The most common goals involved time management and academic performance. Results showed a significant effect for use of incentives/consequences on weekly task completion. Therapist-coach ratings were predictive of task completion, while client ratings were not. The primary barriers to task completion were lack of motivation and poor time management.     

Fraction Instruction for Students with Mathematics Disabilities: Comparing Two Teaching Sequences

Abstract. This study investigated the effects of teaching middle school students with mathematics disabilities equivalent fraction concepts and procedures using the concrete‐representational‐abstract (CRA) instructional sequence or the representational‐abstract (RA) instructional sequence. Twenty‐six students formed the CRA group, and 24 students formed the RA group. The two treatment groups received carefully sequenced instruction over 10 lessons. The only difference between the two treatment groups was that the CRA group used concrete manipulative devices for the first three lessons while the RA group used representational drawings. Analyses of the data indicated that students in both treatment groups improved overall in their understanding of fraction equivalency from pretest to posttest. On all achievement measures, students in the CRA group had overall higher mean scores than did students in the RA group. Implications for classroom instruction and suggestions for further research are discussed.     

Depressive symptoms in young adults: the influences of the early home environment and early educational child care

The relationship between depressive symptoms in young adults, the quality of the early home environment, and early educational child care was investigated in young adults randomly assigned to receive early childhood intervention in the Abecedarian study. Of the original 111 infants enrolled (98% African American), 104 participated in an age-21 follow-up. Those who had early treatment reported fewer depressive symptoms. The protective effects of the early childhood program were further supported by a significant home environment by treatment interaction. Negative effects of lower quality home environments on young adult depressive symptoms were almost entirely offset by preschool treatment, whereas depressive symptoms increased as the quality of the early home environment decreased for those in the control group.