Concurrent schedules: a quantitative relation between changeover behavior and its consequences

Data from several published experiments on concurrent variable-interval schedules were analyzed with respect to the effects of changeover delay on the time spent responding on a schedule before changing to an alternate schedule: i.e., the interchangeover time. Interchangeover time increases as the duration of the changeover delay increases, and the present analysis shows that a power function describes the relation. The power relation applied in spite of numerous differences in the experiments: different variable-interval schedules for the concurrent pairs; equal or unequal reinforcement rates for the schedules of the concurrent pairs; different durations of the changeover delay; response-dependent or response-independent reinforcers; pigeons or rats as subjects; different reinforcers. A power function also described the data in experiments where the changeover incurred a timeout, where a fixed ratio was required to changeover, and also when asymmetrical changeover delays were used.     

On Herrnstein's equation and related forms

In 1970, Herrnstein proposed a simple equation to describe the relation between response and reinforcement rates on interval schedules. Its empirical basis is firm, but its theoretical foundation is still uncertain. Two approaches to the derivation of Herrnstein's equation are discussed. It can be derived as the equilibrium solution to a process model equivalent to familiar linear-operator learning models. Modifications of this approach yield competing power-function formulations. The equation can also be derived from the assumption that response strength is proportional to reinforcement rate, given that there is a ceiling on response rate. The proportional relation can, in turn, be derived from a threshold assumption equivalent to Shimp's “momentary maximizing”. This derivation implies that the two parameters of Herrnstein's equation should be correlated, and may explain its special utility in application to internal schedules.     

BEHAVIOR ANALYSIS APPLIED TO ENVIRONMENTAL/ECOLOGICAL PROBLEMS; A REVIEW1

Recent applications of operant technology, including the manipulation of environmental conditions and response consequences, have been directed toward the improvement of man-environment relations. This document summarizes the research designs, procedures, results, and conclusions of these recent behavioral interventions for ecological rebalance. Each of the 32 studies reviewed was undertaken since 1970; all studies were relatively successful in changing the probability of an ecology-related response; all studies incorporated basic methodologies applicable for large-scale, community programs; most of the investigations were conducted in field settings (e.g., college campuses, grocery stores, mobile-trailer parks, homes, movie theaters, public campgrounds, and a football stadium). Several of the studies are as yet unpublished. Sources for receiving documentation of the unpublished research are provided in this document. About 50% of the investigations reviewed were designed to influence behaviors related to environmental litter; the others were of behavior-modification programs that substantially increased bus-ridership, decreased lawn-trampling, promoted the purchase of drinks in returnable rather than throwaway containers, initiated a recycling process, or reduced energy consumption. Essentially, the interventions were either preventive in nature (i.e., designed to discourage environment-destructive behaviors before they occur), or remedial (i.e., designed to encourage behaviors that correct an existing environmental problem). Usually, the preventive measures emphasized responses priming (or prompting), while the corrective measures applied some form of positive reinforcement. Response priming was accomplished with modelling techniques, or with written and/or verbal prompts presented either publicly or on a personal, one-to-one basis. Among the positive reinforcement procedures were field applications of token economies, lottery systems, feedback programming, and intergroup contests, as well as individual contingency contracting. Some experimental designs provided for comparisons between the behavioral effects of response priming and positive reinforcement.     

TEACHING CONVERSATION-RELATED SKILLS TO PREDELINQUENT GIRLS1

The use of conversation-related skills by youthful offenders can influence social interactions with adults. These behaviors are also likely to be useful to adolescents after their release from a treatment program (Journal of Applied Behavior Analysis, 1972, 5 , 343–372). Four girls, aged 13 to 15 yr, residing at Achievement Place for Girls in Lawrence, Kansas, received training on conversation-related behaviors. A multiple-baseline design across youths and across behaviors was used. Youth answer-volunteering in response to questions and three youth nonverbal components (“hand on face”, “hand at rest”, and “facial orientation”) were measured during daily 10-min sessions with a simulated guest in the group home's living room. Answer-volunteering was scored each session as the per cent of 13 “secondary” questions that the simulated guest did not have to ask following 10 “primary” questions. The three nonverbal components were scored according to their occurrence during 10-sec intervals and the resultant scores were averaged per session for an overall appropriate nonverbal score. The girls individually earned points within the home's token economy for participating in each session and additional points were awarded after training if preselected behavioral criteria were achieved for each of the two behavior categories per girl. Some of the training sessions were led by a “teaching-parent” (specially trained houseparent) while others were led by individual girls. Point consequences were administered by both the teaching-parent and by the “peer-trainers”. The average observed rate of answer-volunteering by the girls during pretraining sessions was 30% for S₁, 30% for S₂, 23% for S₃, and 68% for S₄. The average rate of answer-volunteering during posttraining sessions was: S₁ = 92%, S₂ = 89%, S₃ = 90%, and S₄ = 98%. The average nonverbal score during pretraining sessions was 82% for S₁, 53% for S₂, 60% for S₃, and 82% for S₄. The average nonverbal score during posttraining sessions was: S₁ = 98%, S₂ = 98%, S₃ = 98%, and S₄ = 100%. Videotapes of the sessions were shown in a random sequence to four adults (probation officer, social worker, etc who represented “significant others” for the youths' future success in the community. The adults judged posttraining tapes on the average as more appropriate 100% of the time for S₁, 100% of the time for S₂, 90% of the time for S₃, and 70% of the time for S₄. The study demonstrated that training of conversation-related skills is feasible with predelinquent girls, that the girls can help train each other, and that social validation of the training results is possible.     

SHORT- AND LONG-TERM EFFECTS OF CONTINGENCY MANAGED INSTRUCTION ON LOW,MEDIUM, AND HIGH GPA STUDENTS1

Undergraduate students had been assigned to a contingency managed course or a conventional lecture course (Du Nann and Fernald, Journal of Applied Behavior Analysis, 1976, 9 , 373–374). Two years later, some 35% (N = 86) of the original classes responded to a letter offering them $2.00 to participate in a study of their educational experiences. These students completed a multiple-choice test on material from the course, and answered questions about activities and attitudes that might have been affected by the experience in Introductory Psychology. In the contingency management course 2 yr past, students were tested each week on a chapter of textbook material with 10-item multiple-choice quizzes. The course employed a modified “Doomsday Contingency”, requiring each student to achieve 80% mastery on one of the four weekly quizzes or drop the course. Quizzes were given in small groups and scored individually, while the student stood near, by an undergraduate proctor assigned to that group. The proctor was asked to show interest in the students' quiz performances, help clear up difficult areas, and develop a friendly working relationship with each student. While many students passed the quiz on the first attempt, others were given individual tutoring, so that no one was in fact forced to drop the course. In addition to the weekly quiz assignment, students in the contingency managed group were asked to attend one lecture each week. While the contingency management course procedures had much in common with PSI (Keller, Journal of Applied Behavior Analysis, 1968, 1 , 79–89), several departures made them unique. First, self-pacing was curtailed because students were required to master one unit per week or drop the course. Second, proctors met with students in small groups, usually giving individual tutoring only to those students who did not pass the quiz on the first attempt. Finally, students were asked to attend one lecture per week. Students in the conventional lecture group were not asked to pass weekly quizzes, but instead attended three 50-min lectures each week. Two of these lectures followed the textbook material closely, while the third, which was also attended by students from the contingency management course, covered material only indirectly related to the text. This partition of lecture content allowed material to be similar across the two instructional groups. Although students in the lecture condition were told they could obtain copies of the quizzes, few of them did so. Course grades were determined by scores on two 45-item multiple-choice hourly exams, each covering half the semester material (each worth 25%), and by a 90-item final exam, which served as a measure of short-term retention. Before analyzing the follow-up data, several characteristics of the returning students were compared to determine the comparability of the sample from the two original classes. Most important, both attrition and the current mean GPAs of students from the two classes were very similar. These considerations, and others, suggested there was no systematic sampling bias to confound comparisons of student performance. A 2 (contingency management versus traditional lecture) by 3 (high, medium, and low GPA) analysis of variance was computed on the course final-exam scores and the follow-up measures. Instructional procedure and GPA interacted on the final exam such that low and medium GPA students performed significantly better under contingency management, but there was no significant effect of instructional procedure with high GPA students. On the 2-yr retention measures, students from the contingency management course performed significantly (p < 0.01) better on items drawn from quizzes used in their original course, and marginally better (p < 0.10) on items drawn from the final exams, but no interactions with GPA appeared. Furthermore, instructional method produced no significant main effects or interaction with how many students became majors or minors in psychology, how many psychology courses were later taken, how many books in psychology were reported to have been read, or on students' evaluation of the interest and importance of psychology.     

ACCURACY OF SELF-ASSESSMENT OF ON-TASK BEHAVIOR BY ELEMENTARY SCHOOL CHILDREN1

Being able to assess one's own performance would seem to be prerequisite to most forms of self-management. The present study investigated the extent to which children in a typical second-grade classroom could accurately assess their own academic on-task behavior. In essence, this investigation replicated an experiment by Glynn and Thomas (Journal of Applied Behavior Analysis, 1974, 7 , 299–306) and extended those findings, by studying self-assessment over a longer span of time. The 31 children in the class ranged in age from 7 yr five months to 8 yr six months. Although only eight “problem” children were observed and studied, the self-control treatment procedures were applied to all children in the class. Behavior was observed daily during mathematics lessons for over eight school weeks. The study utilized a five-phase ABABC design, where the A phases were baseline periods, B phases were self-control periods, and C phase was a postcheck. In the self-control phases, children were asked by the teacher to put a check on their own individual performance card if they were on-task when a signal sounded. If they were not on-task, they were instructed not to touch their card. Typically, 15 to 20 signals occurred per 40-min session. At the end of the lesson, children were allowed to choose games to play according to how many checks they had earned. During all experimental phases, observers measured children's on-task behavior. Other observers measured the children's accuracy of self-assessment in the self-control phases. The results showed noticeable increases in the daily mean on-task behavior scores in the self-control phases following baseline phases. Also, a high level of on-task behavior was maintained in the postcheck phase. The variances of on-task behavior scores during the self-control phases were noticeably smaller than those in the baseline phases. Generally, individual data reflected group results, with some minor differences. Levels of accuracy of self-assessment varied from very accurate (95% of the time) to relatively inaccurate (56% of the time). The overall level of accuracy for all children was 78%. No consistent individual pattern appeared across phases. Some children got better as the study proceeded and some got worse. Most subjects tended to give themselves too much reinforcement, rather than too little. Peer social surveillance appeared to be the major factor that influenced individuals' evaluation of their own behavior, even though the teacher did make some control remarks in regard to how the children marked their cards. The results also demonstrated that self-control techniques can increase on-task behavior in a classroom with no history of external reinforcement, and that these techniques can have a lasting effect for more than two months of a school year.     

MODIFICATION OF THE EXCESSIVE INAPPROPRIATE CLASSROOM BEHAVIOR OF TWO ELEMENTARY SCHOOL STUDENTS USING HOME-BASED CONSEQUENCES AND DAILY REPORT-CARD PROCEDURES1

Two experiments investigated home-based reinforcement contingencies to control excessive behavior in normal classrooms. Subjects were, respectively, a 12-yr-old fifth-grade boy and a 9-yr-old fourth-grade boy, each in a separate classroom and with a different teacher. Following baseline observations in which observers recorded several categories of student behavior and teacher-student interaction, separate conferences were held including parents of the two children, the principal, teachers, and experimenters. A daily report-card procedure was agreed on, stipulating a one-day suspension from school following three successive “undesirable” daily report cards as well as the supervision of home-based privileges and other reinforcers usually contingent on satisfactory daily reports. Measurements of daily rates of teacher attention indicated no important change in this variable throughout the various experimental conditions. The daily report procedure significantly reduced disruptive classroom behavior. In a second experiment, a teacher-operated timer cued her own time-sample observations. Reliability measures revealed that the teacher could accurately measure the child's behavior while she was teaching the class. The procedure was ultimately successfully expanded to the teacher's total contact hours each day.     

SELF-RECORDING IN TRAINING GIRLS TO INCREASE WORK AND EVOKE STAFF PRAISE IN AN INSTITUTION FOR OFFENDERS1

Self-recording procedures were used by four adolescent girls to increase work and comments (cues) that evoked staff praise during vocational training sessions in a maximum-security institution for offenders. The girls were selected on the basis of their not responding to a staff-directed token program. The self-recording procedures were directed by a therapist who saw the girls outside the vocational training sessions. According to a multiple-baseline design, self-recording of work was introduced sequentially to each of the two or three settings the girls attended each day. A few days after work had increased, self-recording of cues was introduced. Tokens were delivered by the therapist for work and cues recorded by the girls. Work and cues increased following self-recording for three of the girls and increased cues evoked higher rates of staff praise. Girl and staff behaviors were maintained during short follow-up periods when tokens were not given for the girls' records. The procedures failed to effect desirable changes with a fourth girl's work, and self-recording of work was terminated without introducing cueing.     

Effects of two teacher-presentation rates on off-task behavior, answering correctly, and participation

Off-task behavior, correct answering, and participation during beginning reading instruction were recorded for two low-achieving first-grade children during two different rates of teacher presentation. A slow-rate presentation (A) was compared with a fast-rate presentation (B) in an ABABAB design. In slow-rate presentation, there was a delay between the children's response and introduction of the next task. In fast-rate presentation, there was no delay. A new teacher taught during the final AB phases, which allowed for a brief replication. Both teachers were reminded on a fixed-interval 90-sec schedule throughout all phases of the experiment to praise the subjects, thus preventing a confounding of social praise and rate of teacher presentation. Fast-rate presentation was accompanied by a lower per cent occurrence of off-task behavior for both Subjects 1 and 2. For Subject 1, correct answering and participation were more frequent during all three fast-rate phases. For Subject 2, correct answering and participation were more frequent during the fast-rate phases after the first reversal.     

Clock control of human performance on avoidance and fixed-interval schedules

The avoidance and fixed-interval performances of human subjects were studied in two experiments. Addition of time-correlated stimuli (added clock) improved behavioral efficiency, since response rates decreased without decreases in reinforcement rates. Response-dependent display of the clock maintained a second, observing response and reductions in clock duration weakened such observing behavior. Generally, the reinforcing properties of the clock were more apparent with the avoidance than with the fixed-interval schedule, a finding attributed to temporal cues already provided by delivery of the fixed-interval reinforcers. Reduced rates of the main response when the clock was dependent on an observing response were more than offset by rates of the observing response in the majority of subjects. Thus, the results do not support an interpretation of the reinforcing properties of added clocks simply in terms of work reduction.