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971.
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.  相似文献   
972.
This research examines empirically the relationship between two measures of teacher quality: one based on professional standards and a second one using teacher value-added estimates. It also studies the extent to which teacher observable characteristics, such as teacher training variables, are associated to better performance on either of these measures and whether any of these two assessments is able to effectively measure teacher quality isolated from the effect of the context where teachers work. Context in this article is defined as any variable that is not under the direct control of the teacher but plays an important role on student learning and we believe is captured by school and municipal variables. The study uses hierarchical linear models and information from national and standardized assessments from Chile, specifically from the municipal education sector. Results show a small correlation between the two measures of teacher quality, in the lower end of results from previous studies conducted in the USA, and suggest that there is only a limited relationship between both measures of teacher quality. Teacher initial education type and professional development were statistically associated only to the standard-based measure of teacher quality. Context (both the school and municipal levels) plays an important role in the teacher effect measure, and in the standard-based measures, therefore, we conclude that neither of these measures are context-free. We expect that these results will contribute to the discussion about how to best measure teacher quality and how to evaluate teacher performance both in Chile and other parts of the world.  相似文献   
973.
This article describes the effects of an analysis-of-practice professional development (PD) program on elementary school students' (Grades 4–6) science outcomes. The study design was a cluster-randomized trial with an analysis sample of 77 schools, 144 teachers and 2,823 students. Forty-two schools were randomly assigned to treatment, (88.5 hours) of integrated analysis-of-practice and content deepening PD (over the course of one year) while 35 schools were randomly assigned to receive an equal number of PD hours in science content deepening alone. Students' content knowledge, as measured by a project-specific test, was compared across treatment groups. The effect size for this comparison was 0.52 standard deviations in favor of students whose teachers participated in the PD that included analysis-of-practice. This effect compares favorably to that of other elementary school interventions whose effectiveness was studied with a narrowly focused outcome measure. Analysis of the demographics of the study schools suggests that the treatment effect could be relevant outside the local study context. Implications for future research include tests of mediation for teacher-level outcomes and efficacy tests of specific teaching strategies (intervention subcomponents).  相似文献   
974.
The aim of this explorative study was to develop and test a pedagogy aimed at promoting students’ ability to perform historical contextualization. Teaching historical contextualization was conceptualized in terms of four pedagogical design principles: (1) making students aware of the consequences of a present-oriented perspective when examining the past, (2) enhancing the reconstruction of a historical context, (3) enhancing the use of the historical context to explain historical phenomena and (4) enhancing historical empathy. The effectiveness of these principles was explored in a lesson unit focusing on the seventeenth and eighteenth centuries. In a quasi-experimental pre-test–post-test design with experimental and control conditions, the effects of the pedagogy on 15- and 16-year-old students’ ability to perform historical contextualization were examined (n = 131). The results indicated that students in the experimental condition significantly improved their ability to perform historical contextualization compared to students in the control condition. These findings could be used to help teachers and other educational professionals design and implement historical contextualization tasks and instructions.  相似文献   
975.
This study focuses on parents’ and teachers’ perceptions of practices aimed at easing the transition to formal schooling (e.g., familiarization with the school, discussions about the school entrants). A total of 230 preschool teachers, 131 elementary school teachers, and 2,662 mothers and fathers filled in a questionnaire containing items on how important they considered different preschool-school transition practices. The participants considered the various transition practices to be at least somewhat important. On average, familiarization with the school was considered to be most important, whereas teacher co-operation and joint writing of curricula were considered to be least important. The perceptions of the participant groups differed from each other significantly in almost all practices. We suggest that the information on school entrants should be transferred within joint meetings between transition partners and other professionals whenever possible.  相似文献   
976.
977.
ABSTRACT

Purpose: To analyze the Brazilian experience in designing and implementing a recent extension policy reform based on agroecology, and reflect on its wider theoretical implications for extension reform literature. Design/methodology/approach: Using a critical public analysis we characterize the evolution of Brazilian federal extension policy between 2004 and 2015, using political and legal documents as well as recent academic studies for policy frame characterization and implementation analysis. Findings: The case reveals the difficulty of implementing an agroecological extension approach as part of the endogenous development proposal expressed in 2004 PNATER. The agroecological proposal tended to be impaired by a more general demand for diverse public policy programs implementation, facing a series of institutional constraints. A policy reframing process led to a search for alternatives to make it compatible with a federal centralization trend and public administration rules, resulting in a contracting out emphasis. Theoretical implications: The study shows the political economy aspects of extension reform, and how original plans are influenced by path dependence and different and contrasting demands. Practical implications: The study points to the importance of considering political and institutional environments in extension reforms, and indicates a necessity for additional reflection about strategies for scaling up proposals for agroecological and sustainability oriented extension. Originality/value: Few studies are dedicated to understanding the political economy of extension reform, and reform of Brazilian rural extension systems.  相似文献   
978.
Two studies examine patterns of school readiness in children at school entry and how these patterns predict first-grade outcomes in a nationally representative sample of first-time kindergartners from the Early Childhood Longitudinal Study—Kindergarten Class of 1998–1999 (N = 17,219). In Study 1, cluster analyses revealed four profiles at kindergarten entry: comprehensive positive development (30%), social/emotional and health strengths (34%), social/emotional risk (13%), and health risk (22.5% of the sample). Study 2 results suggested that children with one of the two “risk” profiles were more likely to be from families with multiple socioeconomic disadvantages. In addition, all four profiles differentially predicted academic and social adjustment in early elementary school. Children with a risk profile performed the worst on all outcomes; children with a comprehensive positive development profile performed the best. The authors discuss the need for early identification of children who may be at risk for entering school with few school readiness strengths.  相似文献   
979.
980.
A feminist action research team, which consisted of a science educator, an English‐language learner (ELL) educator, a first‐year science teacher, and a graduate assistant, set a goal to work together to explore the process a beginning teacher goes through to establish a classroom conducive to the needs of middle‐level ELL learners. The guiding questions of the study were answered by gathering a wealth of data over the course of 5 months and taken from the classroom, planning sessions, and researchers and students. These data were collected by observations, semistructured interviews, and written document reviews. The progressive analysis ultimately revealed that: (a) successful strategies a beginning teacher must utilize for teaching middle‐level ELL children in a mainstream classroom involve complex structural considerations that are not part of the teacher's preparation; (b) learning increases for all children, but there are differences in learning achievement between ELL and non‐ELL children; and (c) student and peer feedback proved to be an effective means of enhancing the growth of a beginning teacher seeking to increase her skills in teaching ELL learners. The experiences and findings from this project have implications for teacher preparation programs committed to preparing educators to teach science to all children. © 2005 Wiley Periodicals, Inc. J Res Sci Teach 42: 1013–1031, 2005  相似文献   
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