Human concurrent performances: The effects of experience, instructions, and schedule-correlated stimuli

In order to investigate the effects of separate exposures to single schedules, of unique schedule-correlated stimuli, and of independency-informing instructions upon choice under concurrent variable-interval schedules, 28 human subjects were divided into eight groups. Each subject was exposed to a baseline procedure, an experimental procedure, and a return to the baseline procedure. Different combinations of these three manipulations were applied to the different groups only during the experimental phase (except for the independency-informing instructions, which were given to half of the groups at the start of training). For the group of subjects exposed to the combination of all three manipulations, the logarithms of the ratios of response frequencies tended to be linearly related to the logarithms of the ratios of reinforcement frequencies during the experimental phase. These orderly effects were not obtained with subjects in the other groups. The results suggest that human choice was well described by the generalized matching law when the three manipulations were simultaneously in effect, and that unreported differences in the use of these three procedural variables might partly account for contradictions between results in previous studies of human concurrent performance.     

An analysis of several variables influencing the efficacy of flash card instruction

We conducted four experiments using an alternating treatments design to assess the influence of several variables on children's acquisition of number facts during one-on-one flash card instruction. In Experiment 1, we manipulated the order of stimulus presentation; in most cases a higher percentage of correct responses occurred, and mastery criterion was reached in somewhat fewer sessions, when a missed problem was re-presented after the next item than when problems were re-presented in a sequential order. In Experiment 2 a comparison of error-contingent reprimands with no reprimands yielded similar results in favor of the former procedure. Experiment 3 indicated that a higher percentage of correct responses and more rapid acquisition occurred when the tutor and student were seated knee-to-knee than when a desk was positioned between them. Experiment 4 compared the rate of learning in the presence and absence of a treatment package consisting of all three variables identified as leading to more rapid learning in the previous three experiments. Children reached criterion in less than half the time when the treatment package was in effect.     

A comparison of pacing contingencies in classes using a personalized system of instruction

This study compared the effects of multiple versus single deadline contingencies on distribution of unit-mastery test taking by students in four university classes taught using the personalized system of instruction. Rate of test taking was most uniform when multiple deadlines were imposed throughout the course. When deadlines were infrequent, a scalloped pattern of test taking developed.     

Effects of imposed postfeedback delays in programmed instruction

Imposed postfeedback delays promote discrimination training; the present experiments determined whether they also improve performance in programmed instruction. In two experiments, college students completed 45 sets of Holland and Skinner's (1961) programmed text on behavior analysis in a computerized format in a three-component multiple schedule. In Experiment 1, the conditions were (a) no delay between questions, (b) a 10-s delay after each question (noncontingent delay), and (c) a 10-s delay after each question answered incorrectly (contingent delay). Noncontingent delay produced better performance than no delay and contingent delay. To determine whether performance increased in the noncontingent delay condition because subjects studied the material during delay periods, Experiment 2 tested three conditions: (a) no delay between questions, (b) a 10-s delay after each question (noncontingent delay), and (c) a 10-s delay after each question with the screen blank during the delay period. Noncontingent delay produced better performance than no delay, but there was no difference in performance between no delay and noncontingent delay with blank screen. Hence, noncontingent delay improved performance because students used delay periods to study. Furthermore, subjects preferred noncontingent delay to the other conditions, and session time increased only slightly.     

EFFECTS OF INVENTED SPELLING AND DIRECT INSTRUCTION ON SPELLING PERFORMANCE OF SECOND-GRADE BOYS

Four second-grade boys, 2 rated by their classroom teacher as below average and 2 as above average in basic language skills, participated in a 16-week spelling investigation. The participants alternately received, in counterbalanced order, 5 weeks of an invented spelling approach that incorporated 15-min creative writing periods and 5 weeks of direct instruction that involved 15-min periods of guided practice on spelling word lists. At the end of 10 weeks, each condition was replicated for 3 additional weeks. Although direct instruction resulted in more targeted words spelled correctly, invented spelling resulted in more nontargeted words spelled correctly, higher preference ratings by children, and higher teacher ratings of the quality of 3 of the children's writing samples.