Sources of Inequity: understanding students' responses to assessment

This article considers some of the implications for assessment practice of current views about the nature of learning, and achievement. Evidence from national surveys is presented that demonstrates some of the different ways, ‘tasks' and responses to them are understood by assessors and students. This is followed by a review of evidence about differential sub‐group performance which is then examined to identify potential sources of inequity in assessment practice.     

Inequity as a Source of the Cultural Gap in an Urban School-University Collaborative

Based on a 5-year naturalistic evaluation of an urban university-school collaborative that focused on preparing teachers for urban schools, this analysis was initiated to determine to what extent inequalities between the university and school personnel mitigated the attainment of intended outcomes. Results indicated that some positive change occurred, such as professors and teachers learning to speak the same language on instructional teams, which led to improved field experiences for students. However, cultural differences with concomitant inequities between school and university personnel prevented more permanent change. Inequities of power were inadvertently written into the proposal and were exacerbated at two levels: (1) the collaborative policy board, in which districts, due to larger representation, wielded greater power over budget and hiring in the collaborative; and (2) instructional teams where professors wielded power over several teachers with resistance from teachers. By the end of 5 years, the funded portion of the urban teacher education program that included a collaborative policy board and instructional teams had fallen mostly by the wayside. Cooperation between professors and teachers reverted to precollaborative levels with only loose coupling remaining. Preservice students continue to do field experiences in the professional development schools under supervision. The university education unit recognized the benefits, but continues to struggle with how to revive the level of cooperation that began with the urban program and to create long term partnerships that go beyond mere placement of students into the field.     

Higher order conditioning of a taste aversion

Two groups of rats each received 5 drops of NaCl solution from a dropper placed directly inside the mouth. The experimental group was then injected with lithium chloride to establish a conditioned taste aversion. The control group was injected 24 h later. After a recovery day the above procedures were repeated. On the next day both groups received 5 drops of a saccharin solution followed immediately by 5 drops of the NaCl solution. Subsequent preference tests established that the experimental group had learned an aversion to the saccharin solution as a result of its pairing with the NaCl solution which had previously been associated with poisoning. These results demonstrate that higher order conditioning of a taste aversion can be established using tastes as both the first-order stimulus and the second-order stimulus.     

Sexually dimorphic extinction of a conditioned taste aversion in rats

The existence of a sexual dimorphism in the extinction of conditioned taste aversions in both fluid-deprived and nondeprived rats was investigated. When nondeprived rats were poisoned with LiCl after consuming a sucrose solution, males extinguished the subsequent conditioned taste aversion more slowly than females. There was no difference in the rate of extinction of a LiCl-induced conditioned taste aversion in fluid-deprived rats. Using marihuana extract distillate as the toxin, it was shown that the dimorphism found in the nondeprived rats is not a toxin-specific effect, and does not appear to be due to the males being made more ill. Possible explanations for the appearance of the dimorphism and its relation to the deprivational state of the organism are discussed.     

Food aversion learning in kangaroo rats: A specialist-generalist comparison

Two species of kangaroo rat (Dipodomys), varying in their degree of dietary specialization, were compared in a series of food aversion learning experiments to test the hypothesis that rapid aversion learning is an adaptation of relatively generalist feeders. The more generalist species indeed learned better or more rapidly in certain experiments, but species differences were at least partly a function of the specific test foods. Interpretation of results is complicated by differences between the two species in their initial reactions to particular foods, in the relative efficacy of different foods in supporting learned aversions, and perhaps even in their physiological responses to illness-inducing and control procedures.     

我国义务教育校际资源分配不公平现象的现状、原因及对策

本文通过比较优质学校与普通学校在教育经费收入、教育经费支出、办学条件等方面存在的差异,分析校际资源配置不公平的状况及其形成的原因,并结合教育资源公平分配的五大原则,提出了消除不公平现象的建议,以为推进义务教育公平政策的制订提供参考.     

Spontaneous recovery after extinction of a conditioned taste aversion

Four experiments examined whether or not spontaneous recovery could occur after extinction in the conditioned taste-aversion paradigm. After three extinction trials, spontaneous recovery was obtained over an 18-day retention interval (Experiments 1, 2, and 3). The effect was not due to changes in the unconditioned preference for saccharin over the retention interval (Experiment 2) or to an increase in a nonextinguished aversion over time, as indicated by tests with both the original, nonextinguished aversion (Experiment 1) and with a weaker one (Experiment 3). Spontaneous recovery was not obtained when extinction was overtrained (eight trials) and a 49-day retention interval was used (Experiment 4). However, saccharin intake at asymptote reached the level of baseline water intake, and not the highly preferred level shown by never-conditioned controls. Results of all four experiments suggest that extinction does not return an averted taste to the status of an unconditioned one.     

Timing of interfering events in one-trial serial overshadowing of a taste aversion

This set of experiments examined the question of when a stimulus would be most effective in overshadowing the acquisition of long-delay taste aversion learning. In Experiment 1 rats drank sucrose, the target solution, followed by a hydrochloric acid (HCl) solution before lithium injection some time later; HCl was presented either early or late in the interval. The late condition produced greater overshadowing than the early condition. The importance of the HCl-injection interval was confirmed by Experiment 2, in which the sucrose-injection interval was varied. Experiment 3 found that even placement in a different context – an event that normally produces little overshadowing of a CTA – produced one-trial overshadowing of a sucrose aversion as long as the context was novel and exposure to it occurred immediately before lithium injection. No current theoretical account of one-trial overshadowing predicts that a late event produces more overshadowing than an early event. This result can, however, be accommodated within a modified version of the Rescorla-Wagner model.     

Extinction of a taste aversion in the absence of the consummatory response

Rats were initially conditioned to avoid saccharin presented orally and were then given 40 intravenous injections of saccharin or saline. Those injected with saccharin showed more rapid extinction of the aversion to saccharin presented orally. Results are related to studies of shock avoidance using curarized subjects.     

Long-term retention of a conditioned taste aversion in preweanling and adult rats

The retention and extinction of a conditioned taste aversion after either short (6-day) or long (60-day) intervals was investigated in preweanling (18-day-old) and adult rats. Taste-only and illness-only control conditions were employed, as were variations in the concentration of the US (holding LiCl amount constant). Results indicated that after the short retention interval, retention of the taste aversion was equivalent for both ages. After the long interval, however, the 18-day-old rats exhibited significantly weaker taste aversion than their adult counterparts— infantile amnesia. Manipulation of US concentration had no effect on the magnitude of the taste aversions for either age or retention interval. The results are discussed in terms of their implications for infantile amnesia and general laws of learning.     

一本值得一读的《汉字文化学》

王玉鼎同志二十余万字的著述工程——《汉字文化学》于最近告竣。承蒙他的厚爱 ,我成了此著的第一个读者。在认真读过此著之后 ,我被作者那严谨、认真的治学态度和深厚的文字学、文化学修养所感染 ,亦被此著所蕴藏的知识含量和精深的学术水平所打动。王玉鼎同志用十几年的时间孜孜不倦 ,辛勤探究 ,终于写成并出版了这部学术著作 ,实在可喜可贺 !对于这部学术著作 ,我谈不上有什么深入的理解 ,但我认为它至少有如下几个方面的特点 :第一 ,汉字立论 ,探讨文化。全书基本上都是从汉字的角度出发 ,紧紧抓住汉字的形体、读音和意义这三点来探讨、…     

我国高等教育不公平现象的原因及对策

教育公平近年来一直是学术界关注的热点问题.本文从高等教育不公平的主要危害及解决控制的必要性出发,分析得出制度的设计、执行和监督是造成高等教育不公平的主要原因,同时提出应建立公平的高等教育制度、规范的高等教育执行机制以及完善的高等教育监督机制,以实现高等教育相对公平.     

Amount of training effects in representationmediated food aversion learning: No evidence of a role for associability changes

Rats acquired aversions to food pellets when a previously trained signal for that food was paired with a toxin, but only after minimal signal—food training. After extensive signal—food training, signal—toxin pairings had no effect on food consumption even after manipulations that enhanced the associability of the signal. By contrast, conditioned responding to the signal retained its sensitivity to devaluation of the food reinforcer by food—toxin pairings after extensive training. These results suggest that the nature of associatively activated event representations changes over the course of training.     

Taste aversion learning and schedule-induced polydipsia in rats

Experiment 1 sought to determine whether schedule-induced drinking could be abolished by means of a taste aversion. Polydipsic rats were given access to a .4% saccharin solution while they were exposed to an intermittent food schedule. Immediately after the session, they received an intraperitoneal injection of either lithium chloride or sodium chloride. Following a recovery day with water in the experimental chamber, the animals were again exposed to the saccharin solution. The poisoned animals (lithium chloride) drank very little saccharin compared to the control animals (sodium chloride), indicating that they had learned a taste aversion in only one conditioning trial. Experiment 2 established that polydipsic rats can learn a taste aversion despite a long delay between schedule-induced saccharin consumption and poisoning, and that the delay gradient displayed by polydipsic rats is similar to that observed in thirst-motivated rats.     

Socially induced diet preference can partially reverse a LiCl-induced diet aversion

I examined the capacity of a socially induced enhanced diet preference to reverse the effects of a LiCl-induced diet aversion. I found that rats poisoned after eating a novel diet (Diet NPT) would consume substantial amounts of Diet NPT following interaction with a conspecific that had eaten Diet NPT. Neither rats interacting with a conspecific fed some other diet nor rats exposed to Diet NPT itself exhibited reduced aversion to Diet NPT. This surprising capacity of social interaction to ameliorate even profound toxicosis-induced aversions suggests that social influence may be a major experiential determinant of the diet preferences of free-living rats.