Modeling Self-Regulation as a Process Usinga Multiple Time-Scale Multiphase Latent Basis Growth Model

Measurement burst designs, wherein individuals are measured intensively during multiple periods (i.e., bursts), have created new opportunities for studying change at multiple time scales. This article develops a model that might be useful in situations where the functional form of short-term change is unknown, might consist of multiple phases, and might change over the long term. Specifically, we combine measurement of intraindividual entropy, a latent basis growth model, a multiphase growth model, and a growth model with covariates into a unified framework that could help accommodate the complexity of patterns that emerge in multiple time-scale categorical data streams. Empirical data from a longitudinal study of young children’s behavior during laboratory tasks designed to induce frustration are used to illustrate the utility of the proposed model for simultaneously describing intratask (short-term) change in self-regulation and developmental (long-term) shifts in intratask change.     

Conceptual difficulties experienced by senior high school students of electrochemistry: Electrochemical (galvanic) and electrolytic cells

This research investigated students' understanding of electrochemistry following a 7–9-week course of instruction. A list of conceptual and propositional knowledge statements was formulated, and this provided the framework for semistructured interviews that were conducted with 32 students in their final year of high school chemistry, following instruction in electrochemistry. Three misconceptions identified in this study and five which have been reported earlier are incorporated into an alternative framework about electric current. The framework is grounded on the notion that a current always involves drifting electrons, even in solution. Another area where students' misconceptions were prevalent was in relation to the sign of the anode and cathode. Students who thought the anode was negatively charged believed cations would move toward it, and those who thought it was positively charged were unable to explain why electrons move away from it. Electrolytic cells also proved troublesome for students. Many students did not associate the positions of the anode and cathode with the polarity of the applied electromotive force (e.m.f.). Other students attempted to reverse features of electrochemical cells and apply the reversals to electrolytic cells. The implications of the research relate to students' interpretation of the language that is used to describe scientific phenomena and the tendency for students to overgeneralize, due to comments made by teachers or statements in textbooks.     

Contemporary high-profile scientists and their interactions with the community

This article presents a case study of 10 high-profile Australian research scientists. These scientists are highly committed to engaging with the public. They interact with a wide range of groups in the community, including the traditional media. They are aware that they are seen as representatives of science at a time when the authority of science and scientists is threatened in Australia by controversy around issues such as climate change and vaccination. Through their experiences of interacting with non-scientists, they have developed views about qualities, characteristics and knowledge that contribute to, or inhibit, positive interactions between scientists and non-scientists. Their experiences and insights highlight aspects of contemporary science that are not generally acknowledged in science curricula.     

Retention of conditioned autonomic and behavioral responses in preweanling rats: Forgetting and reinstatement

Preweanling rats, 16 days of age, responded to an olfactory conditioned stimulus (CS) paired with a shock unconditioned stimulus (US) with increases in heart rate and behavioral activation. In two experiments this finding was replicated and, in addition, it was found that the form of these conditioned responses (CRs) changed after a retention interval. When tested 24 h after CS-US pairings, the subjects displayed a decrease in heart rate accompanied by CS-elicited freezing. Giving two unsignaled shocks prior to the delayed test effectively reinstated the tachycardia and behavioral arousal CRs. The results are discussed in terms of contextual influences on the form of the CR and how changes in the magnitude of context fear may alter responding to an olfactory CS.     

Interaction of sample dimension and sample-comparison mapping on pigeons’ performance of delayed conditional discriminations

Coding strategies developed in the acquisition of delayed conditional discriminations can be assessed by independently manipulating sample and comparison memory load. Two stimulus dimensions that can affect memory load were examined: Number of stimuli in the sample and comparison sets (two vs. four) was manipulated between groups in a 2×2 design, and discriminability of sample and comparison stimuli (hues vs. lines) was manipulated between counterbalancing subgroups and within subjects. The results indicated large effects of sample discriminability but not of comparison discriminability, evidence for retrospective coding. There was also a significant effect of number of stimuli in the comparison set (although only with hard-to-discriminate samples) but not of number of stimuli in the sample set, evidence for prospective coding. These findings suggest evidence for retrospective coding with easy-to-discriminate samples, independently of number of stimuli in the comparison set, and evidence for prospective coding with hard-to-discriminate samples.     

The effects of a time-limited welfare program on children: the moderating role of parents' risk of welfare dependency

This study examined the effect of a time-limited welfare program on school-age children using data on almost 3,000 children (ages 5-17 at the four year follow up-point) from the random assignment evaluation of Florida's Family Transition Program (FTP). FTP was one of the first welfare reform initiatives to impose a time limit on the receipt of cash assistance, and it combined the time limit with a rich array of mandatory services. The effects of FTP on children were moderated by families' risk of long-term welfare dependency. Contrary to predictions laid out at the outset, there were few effects of FTP on middle childhood and adolescent children for children of parents most likely to be long-term welfare dependent (those most likely to hit the time limit). However, consistent negative effects on this same age group of children were found for children of parents least likely to be long-term welfare dependent--parents who had the largest employment gains--and effects of FTP were most strongly negative for the oldest adolescent children. The findings suggest a different theoretical model for movements into employment than the one suggested in the previous literature for job loss. The findings are discussed in terms of their contribution to research and policy.     

Pedagogy and possibility thinking in the early years

Connecting to current work in the area of creative pedagogies, this paper reports findings of an exploratory study that sought to identify what characterises possibility thinking in young children's learning experiences and how teachers’ pedagogical practice fosters this critical aspect of creativity. It focuses in particular on pedagogy, seeking to demonstrate how approaches adopted facilitated children's possibility thinking. Possibility thinking has been conceptualised as being central to creative learning although its role, as manifest in the learning engagement of children and the pedagogical strategies of practitioners has not been fully illuminated. The co-participative research team involved in this study comprised staff in an early childhood centre, in an infant and a primary school, working collaboratively with three university-based researchers. The 12-month long segment of a longer study employed various data collection methods including video-stimulated review (VSR) to facilitate reflection, critical conversations, classroom observation, interviews and examination of planning documents. The paper illuminates the perspectives and embedded values that the teachers expressed whilst reflecting upon their practice, and highlights common pedagogical themes, including the practice of ‘standing back’, profiling learner agency and creating time and space. Particular strategies were employed by each of the teachers. These approaches appeared to foster possibility thinking in young learners. In addition, the paper considers the development of the teachers’ thinking through the phases of the research process and presents a model for conceptualising a pedagogy of possibility thinking.     

Discrimination and generalization of leaf damage by blue jays (Cyanocitta cristata)

Blue jays (Cyanocitta cristata) responded to projected black-and-white silhouettes of cherry leaves that were either undamaged or were damaged by either cryptic caterpillars that disguise leaf damage due to their feeding or by noncryptic caterpillars that do not disguise leaf damage due to their feeding. Pecks to the key on which the images were projected were reinforced only if interresponse times fell within specified temporal boundaries. These boundaries were different in the presence of the two types of leaf damage. Following training with one exemplar of each damage type, the jays correctly categorized novel instances of both types. They categorized novel undamaged leaves as if they were examples of leaves showing damage by cryptic caterpillars. Results suggest that the jays can readily discriminate and generalize to new members of a polymorphous stimulus class. The results suggest that techniques for the study of concept formation in animals can be applied to an animal’s ability to categorize stimuli that are involved in a potential prey-predator relationship.     

An engineering application for hypertext

This paper discusses the underlying framework for the protetype of a Hypertext-based tool for the preparation of on-line Design Brief Expansion (DBE) Documents as applied to a systematic design process. It describes the mapping of the DBE into Hypertext and shows how the electronic version of this process is not only more efficient, but also conveys more accessible information than a traditional paper version. It also explains how a natural language system (chunker) can be used to structure the information. The paper concludes with an assessment of how the prototype, implemented in C and HyperNeWS, will be used and a discussion of future improvements.