The role of habituation of the response to LiCl in the US-preexposure effect

In two experiments, rats received preexposure consisting of six intraperitoneal injections of lithium chloride (LiCl). This treatment reduced the magnitude of the unconditioned response (UR; suppressed consumption of a novel flavor) evoked by an additional injection (Experiment 1) or by oral consumption (Experiment 2) of LiCl. In both experiments, preexposure also attenuated the acquisition of a conditioned aversion with an LiCl injection as the unconditioned stimulus (US) but had no effect on the aversion produced when the US was oral consumption of LiCl (Experiment 2). These results are consistent with the view that the reduced ability of the preexposed US to serve as a reinforcer depends on blocking by injection-related cues and is independent of habituation of the UR recorded in the present study. Possible interpretations of this dissociation are discussed.     

Exploring sex differences in science enrolment intentions: An application of the General Model of Academic Choice

In many countries there remain substantial sex differences in enrolments in elective science courses, despite concerted efforts in recent years to alleviate them. This paper explores the reasons for these differences by comparing models of male and female enrolment intentions in elective courses in biology, chemistry and physics. The models are based on responses from approximately 450 students from 5 Australian high schools. First, a theoretical model, the Science Enrolment Model, was derived from Eccles and colleagues’ General Model of Academic Choice. Students’ responses were then used to develop empirical models of enrolment intentions in the three elective courses. Analyses for the models were conducted using the LISREL “mean structures” extension. Sex differences in the dependent variables in the models were then attributed to the relevant sets of independent variables. Substantial sex differences were identified in measures of perceived career value, interest and performance expectations in all three models which explained between 70% and 82% of the sex differences in enrolment intentions.     

Educational Contestability

ABSTRACT The paper considers the implications of the concept of the essential contestability of education for the professional independence of teachers. Its conclusion is that liberal educational ideas provide the strongest theoretical framework for such independence, with child-centred ideas a not very close second. Potential dangers to teachers' professional autonomy from transcendentalist, instrumentalist and reconstructionist theories of education are highlighted. The paper does not endorse unlimited contestability or unrestricted professional independence for teachers and outlines conditions, related to the Paradox of Freedom, in which restrictions are fully justifiable. However, it concludes that in contemporary liberal-democratic societies constraints on educational contestability should be as minimal as possible.     

An Innovative Higher Education Course to Meet Industry's Needs

This paper describes the development and implementation of a multilevel undergraduate degree course in technology management designed to meet identified needs of manufacturing industry. The program has a number of innovative features, including flexible entry and exit points and three levels of award, and is delivered in the workplace with the aid of a computer managed learning system and self paced learning materials supported by electronic mail and workplace tutorials. A feature crucial to its success is extensive collaboration with industry, a partnership with a technical and further education college, and cooperation between applied science and business faculties. An evaluative account of the implementation of the program in two motor vehicle manufacturing plants during 1990, and a discussion of the implications of the findings of the evaluation are also included.     

Enacting silence: Residual categories as a challenge for ethics,information systems,and communication

Residual categories are those which cannot be formally represented within a given classification system. We examine the forms that residuality takes within our information systems today, and explore some silences which form around those inhabiting particular residual categories. We argue that there is significant ethical and political work to be done in exploring residuality.     

The influence of context-reinforcer associations on instrumental performance

In each of two experiments, rats were trained to press the lever in a Skinner box, food reinforcement being available on a variable-interval 60-sec schedule (VI 60). There followed an “exposure phase” for which the levers were removed from the boxes, and then a final test with the levers replaced to assess the effects of the intervening treatment on instrumental responding. Experiment 1 showed that simple exposure to the box reduced the vigor of instrumental performance in comparison with a condition in which food was made available during the exposure phase. Animals which received no exposure treatment also showed a relatively high rate of response. Experiment 2 demonstrated that an exposure treatment in which the occurrence of food is signaled by a light stimulus also leads to a decline in instrumental responding. These results are held to support the notion that associations between the context and the reinforcer serve to energize appetitive instrumental behavior.     

Children's Developing Mathematics in Collective Practices: A Framework for Analysis

This article presents a cultural-developmental framework for the analysis of children's mathematics in collective practices and illustrates the heuristic value of the framework through the analysis of videotaped episodes drawn from a middle-school classroom. The framework is presented in 2 related parts. The first targets the children's emerging mathematical goals in collective practices, with a particular focus on the complex role that artifacts play in children's emerging goals. The second part focuses on children's developing mathematics that takes form in their goal-directed activities: (a) Microgenetic analyses concern the process whereby children structure cultural forms like artifacts to serve particular functions as they accomplish emerging mathematical goals; (b) sociogenetic analyses concern the spread or travel of mathematical forms and associated functions within a community of individuals; and (c) ontogenetic analyses concern the interplay between the forms that children use and the functions that they serve over the course of children's development. The analyses of the classroom episodes points to the promise (and limitations) of the framework as a method for furthering our understanding of the interplay between social and developmental processes in children's mathematics.