Perseveration of associative strength in rabbit nictitating membrane response conditioning following ISI shifts

The present experiment determined whether associative strength based upon 15 CS-US pairings at various interstimulus intervals (ISIs) could survive shifts of the ISI to influence the subsequent acquisition of the nictitating membrane (NM) CR. The choice of 15 preshift pairings was based upon previous work, which had shown that this training level produced substantial associative strength without NM CR acquisition. Consequently, this experiment, by shifting the ISI before the beginning of CR acquisition, served as an extension to traditional ISI-shift studies that have imposed the manipulation after CR acquisition. The findings of the experiment indicated that 15 preshift pairings in Stage 1 at ISIs from 250 to 4,000 msec were as effective as 15 pairings at a 500-msec ISI in determining the number of trials to the first NM CR in Stage 2 in which the training ISI was 500 msec. Moreover, 15 pairings in Stage 1 at ISIs from 250 to 2,000 msec were equivalent to 15 pairings at 500 msec in controlling the number of trials to 10 successive NM CRs in Stage 2. These outcomes demonstrate that, within a large ISI range, the associative strength based upon relatively few pairings is preserved despite various shifts of the ISI. Therefore, these results suggest that the reductions in CR performance, which have been consistently observed in traditional studies following ISI shifts, are not due to the loss of associative strength.     

How infants use vision for grasping objects

The role of vision was examined as infants prepared to grasp horizontally and vertically oriented rods. Hand orientation was measured prior to contact to determine if infants differentially oriented their hands relative to the object's orientation. Infants reached for rods under different lighting conditions. Three experiments are reported in which (1) sight of the hand was removed (N = 12), (2) sight of the object was removed near the end of the reach (N = 40, including 10 adults), and (3) sight of the object was removed prior to reach onset (N = 9). Infants differentially oriented their hand to a similar extent regardless of lighting condition and similar to control conditions in which they could see the rod and hand throughout the reach. In preparation for reaching, infants may use the current sight of the object's orientation, or the memory of it, to orient the hand for grasping; sight of the hand had no effect on hand orientation.     

Analysis of instruction for critical thinking in distance learning materials

This paper discusses procedures for the analysis of instructional strategies incorporated into distance learning materials, especially with regard to the development of the higher order cognitive ability—critical thinking. It examines the function of task analysis as an integral part of the instructional design process, analysing three different approaches available to the instructional designer towards the analysis of tasks required of distance learners. Comparing the learning hierarchy, the concept hierarchy, and the information processing approaches, it was found that the latter was the only one suitable for this current study because of the requirement that critical thinking be linked with domain‐specific knowledge, rather than be learned as an independent ability. Different algorithms for both the student and the designer/analyst are included as part of the information processing approach, and, although these methods are yet to be validated, they seem to offer sufficient promise, while allowing the analyst to make further decisions during the analysis.     

Promoting access, accommodations, and independence for college students with learning disabilities.

This article focuses on the four primary issues that directly affect service delivery to students with learning disabilities in postsecondary settings, including (a) How are high school and post-secondary settings different? (b) How are eligibility and access determined? (c) How are reasonable accommodations determined? and (d) How can the independence level of college students with learning disabilities be fostered? Each of these issues will be discussed within the context of the student's transition from high school, where Public Law 94-142 is in effect, to college, where Section 504 of the Rehabilitation Act of 1973 applies.     

Preservice teachers’ use of contrasting cases in mathematics instruction

Drawing comparisons between students’ alternative solution strategies to a single mathematics problem is a powerful yet challenging instructional practice. We examined 80 preservice teachers’ when asked to design a short lesson when given a problem and two student solutions—one correct and one incorrect. These micro-teaching events were videotaped and coded, revealing that fewer than half of participants (43%) made any explicit comparison or contrasts between the two solution strategies. Those who did were still not likely to use additional support strategies to draw students’ attention to key elements of the comparison. Further, correlations suggest that participants’ mathematical content knowledge may be related to whether participants’ showed contrasting cases but not to whether they used specific pedagogical cues to support those comparisons. While these micro-teaching events differ from the interactive constraints of a classroom, they reveal that participants did not immediately orient toward differing student solutions as a discussion opportunity, and that future instruction on contrasting cases must highlight the utility of this practice.     

Science diaries: a brief writing intervention to improve motivation to learn science

This study investigated the hypothesis that prompting students to self-assess their interest and understanding of science concepts and activities would increase their motivation in science classes. Students were randomly assigned to an experimental condition that wrote self-assessments of their competence and interest in science lessons or a control condition that wrote summaries of those same lessons. Writing activities were 10?min long and were given approximately once a week for eighteen weeks. Student motivation was assessed via self-report surveys for achievement goals and interest in science before and after the intervention. Students in the experimental condition showed higher endorsement of mastery goals and reported greater situational interest in science topics after the intervention compared to students who summarised the lessons. Increases in situational interest predicted higher individual interest in the domain. Results indicate an instructional practice requiring just 3?hours out of a semester of instruction was sufficient to achieve these effects on motivation in science classes.     

Factors affecting rats’ location during conditioned suppression training

If freezing underlies barpress conditioned suppression, then it seems odd that auditory cues paired with shock evoke more freezing than do visual cues, yet evoke similar suppression. Bevins and Ayres (1992) found that auditory and visual cues also evoked similar withdrawal from the bar and dipper areas and suggested that such withdrawal could explain the similar suppression. Seeking to understand that withdrawal, we found evidence in the present study that it was due either to adventitious punishment or to place-aversion learning. The cue for shock seemed to set the occasion for such learning. For example, we found that, as training progressed, rats’ tendency to leave the bar area during the cue first increased, then decreased, then increased again, reflecting, presumably, shock occurrence first inside, then outside, then inside the bar area again. Despite these changes in the rats’ location, barpress suppression remained stable, implying that leaving the bar area, though sufficient for barpress suppression, is unnecessary.     

Integration of reinforcement effects over time

Two accounts of how density of reinforcement affects steady-state performance on probabilistic schedules were compared: the real-time linear operator (RTLO) model and a temporal control model (in which response strength is determined by reinforcement probability as a function of postreinforcement time). In Experiment 1, the probability of reinforcement repeatedly cycled between extinction and a random-ratio 10 schedule. Response-rate gain and phase did not change with period of the cycle as predicted by the RTLO model, nor did either model predict the differences in response rate following reinforcement at different points in the cycle. In Experiment 2, the probability of reinforcement was elevated immediately following a reinforcement but fell after a few seconds. Previous reinforcements had no effect upon responding. An extension of the temporal control model, the cumulative impulse model, allowed for the summing of response strength over successive reinforcements and was consistent with the data of both experiments.     

Stimulant medication and reading performance: follow-up on sustained dose in ADHD boys with and without conduct disorders.

The study examined the sustained effects of methylphenidate on reading performance in a sample of 42 boys, aged 8 to 11, with attention deficit-hyperactivity disorder (ADHD). Two subgroups were formed based on the presence or absence of co-occurring conduct disorders. Subjects were selected on the basis of their positive response to methylphenidate as determined in a series of original medication trials (Forness, Cantwell, Swanson, Hanna, & Youpa, 1991). For the purpose of this study, subjects were placed on their optimal dose of medication for a 6-week period and then tested on measures of oral reading and reading comprehension equivalent to those used in the original trials, retested after a week without medication (placebo), then tested again the following week after return to medication. Only the subgroup with conduct disorders responded, and this response was limited to reading comprehension improvement in only those subjects who also demonstrated improvement in oral reading on original trials. No response differences were found between subjects with or without learning disabilities.     

PPBS in higher education planning and management: Part I,an overview

Higher education in the United States and elsewhere is beset by crises: crises of public confidence, questions of continuing relevance, doubts about continuing the emphasis on doctoral instruction, and a very real financial crisis. In response, governing boards and governmental agencies are devoting increasing attention to the management of higher education. Part of this response has been a heightened interest in formal planning-programming-budgeting-systems (PPBS); in fact, several states have legislated the adoption of PPBS for higher educational planning and decision making. Similar interest has been evidenced in other countries. Therefore, it is an appropriate time to reconsider the nature and role of PPBS and its potential impact on higher education. This paper describes the salient characteristics of PPBS and traces the development of PPBS and related analytical techniques in governmental agencies and institutions of higher education. A second paper will illustrate both the concepts and the implementation of PPBS by a detailed exposition of the University of California's experience with PPBS. Finally, in a third paper we suggest an alternative view of policy analysis for educational planning which is a departure from traditional PPBS. We conclude with general observations and specific recommendations to educational managers seeking to improve their resource allocation procedures.