The life and times of PSI

This paper describes the essential features of the personalized system of instruction (PSI). Results from outcome research examining the effectiveness of PSI-based courses relative to traditional methods provide unequivocal support for the superiority of PSI. Parametric studies, or component analyses, show that the mastery requirement, immediate performance feedback, and review units are the key features underlying high quality student performances in PSI courses. The use of student proctors as peer-tutors, optional lectures, and selfpacing do not, in and of themselves, appear to be vital to student success in PSI courses. Despite its superiority, PSI has not supplanted traditional methods as the dominant pedagogical system in higher education. Difficulties inherent in overcoming the inertia of the lecture within our established instructional system, the implications of PSI for that system, and the Zeitgeist that permeates educational reform are the major obstacles to widespread adoption of PSI.     

The preembryo as potential: a reply to John A. Robertson.

...In conclusion, let me agree with Robertson that reasonable persons may indeed disagree on concrete conclusions touching preembryo freezing, discard, research, and diagnosis. But it is one of the challenges to reasonable people to give reasons for their conclusions. When Robertson notes that preembryo research "has been found acceptable by most bodies that have examined the subject," he leaves unstated the fact that many of these bodies have not given reasons for their conclusions. This is especially true of the Warnock Committee. It is definitely not true of John Robertson. He has attempted to give analytic support for his rather permissive positions. I find this support too fragile for its assigned task, though I hasten to say that this does not mean that only a totally prohibitive position is defensible or is mine. Prima facie still means prima facie.     

Teaching minority high school students to recruit helpers to attain personal and educational goals

Recruiting help from mentors and other potential helpers is a promising strategy for helping disadvantaged and minority youths meet their personal and educational goals. Three African-American high school seniors participated in a project designed to evaluate the effectiveness of training procedures that would allow them to ask for help in attaining educational and other personal goals. A behavioral training procedure that included instructional materials, role-play practice, praise, and feedback was used. Targeted skills included goal setting and 30 responses involved in the process of meeting with a potential helper. Role-play situations were used to evaluate participants' help-recruiting skills before and after training. Participants increased their help-recruiting skills from an average of 38% during baseline, to an average of 75% after training. Self-reported measures of goal attainment suggested that the students benefited from the training. Implications for mentoring programs designed to increase minority students' opportunities to reach educational goals were discussed.     

Computers and computing in psychology: Twenty years of progress and still a bright future

Computers and technology in psychology can be a cornucopia or a Pandora’s box. During the 20 years of its existence, the Society for Computers in Psychology has been an important focus for the appropriate and beneficial application of computing technology in psychology. Although the increase of computer use is unmistakable, cyclic trends in computer applications also can be identified and, together with current technological developments, lead to predictions, concerns, and challenges for the future.     

Spatial judgments of exocentric extents in an open-field situation: Familiar versus unfamiliar size

Carlson and Tassone (1971) found that an object of familiar size presented in an outdoor setting and viewed at an appreciable distance is judged to be more distant than an unfamiliar object. Three experiments examined whether object familiarity also affects spatial judgments of exocentric extents presented under conditions comparable to those of Carlson and Tassone’s experiments. The markers of the extents were either familiar or unfamiliar objects. In Experiment 1, subjects reproduced the perceived extents of depth intervals by adjusting a comparison egocentric extent, and in Experiment 2, subjects also compared the relative depths of two equally long extents. In Experiment 3, the two equally long extents were presented in the subjects’ frontoparallel plane, and the subjects reported which of these two extents appeared longer and farther away. The results of these experiments indicate that familiar size does not affect the perceived depths or lengths of exocentric extents viewed under naturalistic conditions.     

The time course of extinction-induced aggressive behavior in humans: Evidence for a stage model of extinction

Three experiments examined the effects of extinction on aggressive responding in male college students. In Experiment 1 subjects initially performed on a task where shuttle responding was either continuously or partially reinforced with tokens while either a nonaggressive button-pressing response or an aggressive pad-striking response was concurrently reinforced by escape from a moderately aversive tone. During shuttle acquisition there was clear preference for the escape response of button pressing, but when shuttle responding was extinguished subjects began to respond aggressively by striking the pad to escape. The time course of aggressive escape responses during concurrent shuttle extinction was an inverted U; aggressive responding rose to a peak and then declined. Aggressive responding began earlier in extinction following continuous- as contrasted with partial-reinforcement shuttle training. Experiment 2 showed that similar extinction-induced aggression was precipitated by both moderate and extended continuous-reinforcement shuttle training, with earlier onset after extended reinforcement. Experiment 3 ruled out the possibility that the emergence of the pad-striking response during extinction was simply induced response variation. These data were interpreted within the theoretical framework of P.T.P. Wong's recently advanced stage model of extinction (Animal Learning and Behavior, 1978,6, 82–93).     

Lithium-mediated disruptions of latent inhibition: Overshadowing by the unconditioned stimulus in flavor conditioning

In a series of experiments, the ability of a single lithium preexposure to disrupt CS effectiveness was assessed using a latent inhibition procedure. Lithium preexposure administered proximal (90 min) to a saccharin familiarization trial reduced latent inhibition whereas a similar administration more distal (360 min) to flavor familiarization failed to do so. Additional experiments demonstrated that this socalled “US overshadowing” effect was not attributable to sensitization (Experiment 2), excitatory backward conditioning (Experiment 3), or state dependency (Experiment 4). The implications of US overshadowing for proximal US-preexposure effects are discussed.     

Ordered binary trees constructed through an application of Kendall's tau

A procedure is described for orienting the nodes of a binary tree to maximize the Kendall rank order correlation (tau) between node order and a given external criterion. The procedure is computationally efficient and is based on application of an ordered set of node tests.     

Canonical analysis of longitudinal and repeated measures data with stationary weights

When measuring the same variables on different occasions, two procedures for canonical analysis with stationary compositing weights are developed. The first, SUMCOV, maximizes the sum of the covariances of the canonical variates subject to norming constraints. The second, COLLIN, maximizes the largest root of the covariances of the canonical variates subject to norming constraints. A characterization theorem establishes a model building approach. Both methods are extended to allow for Cohort Sequential Designs. Finally a numerical illustration utilizing Nesselroade and Baltes data is presented.The authors wish to thank John Nesselroade for permitting us to use the data whose analysis we present.