Intelligent use of the many diverse forms of data available on the Internet requires new tools for managing and manipulating
heterogeneous forms of information. This paper uses WHIRL, an extension of relational databases that can manipulate textual
data using statistical similarity measures developed by the information retrieval community. We show that although WHIRL is
designed for more general similarity-based reasoning tasks, it is competitive with mature systems designed explicitly for
inductive classification. In particular, WHIRL is well suited for combining different sources of knowledge in the classification
process. We show on a diverse set of tasks that the use of appropriate sets of unlabeled background knowledge often decreases
error rates, particularly if the number of examples or the size of the strings in the training set is small. This is especially
useful when labeling text is a labor-intensive job and when there is a large amount of information available about a particular
problem on the World Wide Web.
The perceived spatiotemporal continuity of objects depends on the way they appear and disappear as they move in the spatial layout. This study investigated whether infants' predictive tracking of a briefly occluded object is sensitive to the manner by which the object disappears and reappears. Five-, 7-, and 9-month-old infants were shown a ball rolling across a visual scene and briefly disappearing via kinetic occlusion, instantaneous disappearance, implosion, or virtual occlusion. Three different measures converged to show that predictive tracking increased with age and that infants were most likely to anticipate the reappearance of the ball following kinetic occlusion. These results suggest that infants' knowledge of the permanence and nonpermanence of objects is embodied in their predictive tracking. 相似文献
OBJECTIVES: To assess the impact of a voluntary, paraprofessional home visiting program in preventing child maltreatment and reducing the multiple, malleable psychosocial risks for maltreatment for which families had been targeted. METHODS: This collaborative, experimental study focused on 6 Healthy Families Alaska (HFAK) programs; 325 families were enrolled in 2000-2001, randomized to intervention and control groups, and interviewed to measure baseline attributes. Follow-up data were collected when children were 2 years old (85% follow-up rate). Outcomes included maltreatment reports, measures of potential maltreatment and parental risks, for example, poor mental health, substance use, and partner violence. HFAK records were reviewed to measure home visiting services. Home visitors were surveyed to measure perceived effectiveness and training adequacy. RESULTS: Parental risks were common at baseline, and one-sixth of families had a substantiated child protective services report in the child's first 2 years of life. There was no overall program effect on maltreatment reports, and most measures of potential maltreatment. Home visited mothers reported using mild forms of physical discipline less often than control mothers. The groups were similar in their use of more severe forms of physical discipline. There was no program impact on parental risks. There was no impact on outcomes for families with a 'high dose' of home visiting. Home visitors often failed to address parental risks and seldom linked families with community resources. Contradictions in the model compromised effectiveness. CONCLUSIONS: The program did not prevent child maltreatment, nor reduce the parental risks that had made families eligible for service. Research is needed to develop and test strategies to improve the effectiveness of home visiting. 相似文献
Engaging students in a challenging (cognitively demanding) task and launching a mathematics lesson with a task before instruction are two characteristics of a reform-oriented approach to mathematics instruction often considered together. The authors systematically contrasted teaching with challenging tasks using a task-first lesson structure with that of a discussion-first lesson structure to three composite classes of first- and second-grade students (n = 73). Subsequent assessments of mathematical performance revealed that the discussion-first lesson structure was somewhat more efficacious in improving fluency performance but both structures similarly improved problem-solving performance. The findings suggest there is more than one way of incorporating challenging tasks into mathematics lessons to produce sizeable learning gains. 相似文献
This mixed-methods study examines engaging teaching at one racially and ethnically diverse public school using the self-system process model of student engagement. As theorized, multilevel analyses of student survey data (N?=?580) reveal that student perceptions of structure, autonomy support, and involvement differentiate highly, moderately, and weakly engaging teachers. Classroom observations (N?=?12) and student interviews (N?=?17) suggest that the behavior of autonomy supportive and involved teachers is friendly, helpful, and emphasizes student agency. Although few racial or ethnic differences are observed, autonomy supportive and involved teacher behavior appears particularly critical to the behavioral engagement of Black and Latinx students. Helpfulness may also moderate stereotype threat. Implications for researchers, practitioners, and policy-makers are discussed.
This article builds upon a tradition of feminist critical engagements with Bourdieu, developing the concept of ‘foregrounded history’ as a way to conceptualise the temporal and affective in processes of habitus formation. Through analysis of affects ‘produced through the social encounter’ within everyday childhoods on a British council estate, the article explores habitus as histories both embodied and felt in the present. Drawing upon ethnographic research conducted within the interrelated fields of the Primary School and the Community Centre, this article considers processes of distinction, disagreement and resistance in the formation of classed positionings on The Estate. 相似文献
Primary objective: Teacher evaluation is being revamped by policy-makers. The marginalized status of physical education has protected this subject area from reform for many decades, but in our current era of system-wide, data-based decision-making, physical education is no longer immune. Standardized and local testing, together with structured observation measures, are swiftly being mandated in the USA as required elements of teacher evaluation systems in an effort to improve school programs and student achievement. The purpose of this investigation was to document how this reform was initiated and the experiences of teachers, students and administrators, from three high school physical education programs, during initiation of this reform. Documenting how physical education programs respond to such reforms develops our understanding of top-down reform efforts and helps to identify conditions under which such reforms have the intended effect on physical education teachers and student learning in physical education.
Theoretical framework: Fullan’s three phases of school change has been used to analyze and guide school change efforts in several subject areas including physical education. The phases are initiation, implementation and institutionalization. This study is situated primarily within the first phase of school change, the initiation phase.
Methods and procedures: This study took place over a 21-month period in 3 suburban school districts in a northeast metropolitan area of the USA. Interviews with district physical education administrators, high school physical education teachers and students were conducted. Field notes of physical education classes, informal interviews and related artifacts including pre- and post-physical education assessments were collected. To ensure trustworthiness, several steps were taken including member checks, triangulation and peer review. The data were analyzed to find common themes and patterns using the constant comparative method.
Results: Several themes emerged: (1) changes in curriculum and assessment; (2) effect on administrators; (3) stakeholder apathy and (4) department collaboration.
Conclusion: Changes, although minor, did take place in the wake of this top-down teacher reform; however, additional research needs to be completed to determine whether or not these changes are meaningful or long lasting. 相似文献