AN EXPERIMENTAL COMPARISON OF A CONTINGENCY MANAGED COURSE WITH LARGE LECTURE METHOD1

Contingency management procedures resembling the Personalized System of Instruction (PSI) were compared with a conventional lecture method in teaching an introductory psychology course. The use of a within-subjects design in which half of the students experienced both teaching conditions made it possible to examine the reliability of test-score differences over time when subjects were balanced over conditions. In the contingency management course, material was broken down into 14 small units, each unit covering about 30 pages of text. Students were assigned to an undergraduate teaching assistant who was encouraged to develop a close working relationship with each of his/her 13 assigned students. Specifically, this meant that the assistant was to call each student by his/her first name, show an interest in the student's quiz performance, help the student understand difficult concepts, and discuss various topics of interest to the student. Each week, the teaching assistant administered up to four different 10-item multiple-choice quizzes over the week's chapter. A modified “Doomsday Contingency” required each student either to achieve a score of 80% on one of the four quizzes or drop the course. Most students passed the quiz during the first session of the week; those not passing were tutored on special areas of weakness. No student was actually forced to leave the course under the Doomsday Contingency. Although quizzes were administered on a group basis, they were scored individually while the student stood near by. In addition to the weekly quiz assignment, students under the contingency management procedures were asked to attend one lecture per week. The contingency management method departed from traditional PSI in that (1) self pacing was minimal, such that students were required to master one unit per week or drop the course, (2) teaching assistants met with students in small groups, and usually gave individual tutoring only to those students who did not pass the quiz on the first attempt, and (3) students were asked to attend one lecture per week. However, it was similar to PSI in that small units of subject matter were assigned and unit mastery was assessed through use of undergraduate assistants who delivered immediate feedback. Students in the conventional lecture group attended three 50-min lectures each week; two of these lectures followed textbook material closely, while the third, which was attended by all students, concerned material only indirectly related to the text. As a result, students in both conditions were exposed to essentially identical material. Students in the lecture condition could also obtain copies of the unit quizzes, although few did so. Course grades were determined by scores on two 45-item multiple-choice hourly exams, each covering half of the semester material (each worth 25%), and by a 90-item final exam over the entire course (worth 50%). These measures also served as the dependent variables. The experimental design employed a crossover technique in which one fourth of the students began with the contingency management method and then switched to lecture method at midsemester, while another fourth began with the lecture method and switched to contingency management. The other students stayed in the same condition throughout the semester, half under contingency management and half under the lecture method. On the last day of class, all students filled out an extensive questionnaire that assessed their opinions and attitudes about the teaching techniques. In addition to allowing for assessment of any progressive effects that the contingency management procedures might have had over time, the crossover design also permitted students to make meaningful comparisons of the two teaching methods, since half of the students experienced both methods in the same course. Although average test performance was only slightly higher under the contingency management condition, this difference occurred on each exam and was statistically reliable in each case. Further, the method did not interact with time, as it produced about a three-item advantage per half semester. On each of the three exams, teaching method accounted for between 5 and 8% of the total variance in test scores. Finally, attitude measures indicated that students experiencing half a semester of the contingency management procedures preferred them to the lecture technique, but that only those students with a full semester of contingency management rated the course significantly better than students in the full semester lecture course.     

Opportunities and Issues in Modeling Intensive Longitudinal Data: Learning from the COGITO Project

Abstract

Technological developments increasingly permit the collection of longitudinal data sets in which the data structure contains a large number of participants N and a large number of measurement occasions T. Promising new dynamical systems approaches to the analysis of large N, large T data sets have been proposed that utilize both between-subjects and within-subjects information. The COGITO project, begun over a decade ago, is an early large N?=?204, large T?=?100 study that collected high quality cognitive and psychosocial data. In this introduction, I describe the COGITO project and conceptual and statistical issues that arise in the analysis of large N, large T data sets. I provide a brief overview of the five papers in the special section which include conceptual pieces, a didactic presentation of a dynamic structural equation approach, and papers reporting new statistical analyses of the COGITO data set to answer substantive questions. Although many challenges remain, these new approaches offer the promise of improving scientific inquiry in the behavioral sciences.     

Time-dependent changes in conditioned suppression

Time-dependent changes in a response following aversive conditioning were investigated using a conditioned suppression procedure in a within-subjects design. Four groups of pigeons received Pavlovian conditioning “off the baseline”, immediately followed by an operant task. During the Pavlovian phase, two groups received a forward pairing of a tone with shock, one group received a backward pairing, and one group received a truly random pairing. One of the forward pairing groups also received a delay between the Pavlovian and operant phases. For all groups, key pecking was reinforced on a variable-interval schedule during the operant phase. Testing sessions were identical to training sessions, except that the tone used during Pavlovian conditioning was presented either 0, 15, 30, 45, of 60 minutes after the operant phase began. Testing sessions in which the Pavlovian phase was omitted were also included. The results showed suppression to change as a function of the retention interval, with maximum suppression occurring at intermediate intervals. This U-shaped function was obtained for 11 of the 12 pigeons in the forward-pairing groups and for three of the five in the truly random group. Pigeons in the background pairing group did not show changes in suppression as a function of the retention interval.