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Robert B. Horwitz 《The Information Society》2005,21(3):181-204
Corporate mergers and the consolidation of ownership in the American communications arena have long been sources of concern. U.S. regulatory and antitrust policy traditionally attempted to secure a “diversity of voices” structurally, largely through rules regarding ownership. Although the meaning of diversity was always problematic and undertheorized, the Federal Communications Commission long set ceilings on the numbers of broadcast outlets any single person or corporation could own and enacted cross-ownership rules such as a prohibition against a corporation owning a newspaper and broadcast outlets in the same market. These rules, and the FCC's authority to make them, were upheld, occasionally even compelled, by the federal appellate courts. In the last 20 years, however, legal trends, in conjunction with political developments, have undermined the diversity rationales behind ownership rules and associated structural regulations of mass media. Paradoxically, even as media corporations are becoming larger and presumably more powerful, ownership regulations are being rescinded or struck down. This article explains this history. It concludes with a suggestion that the First Amendment metaphor of a marketplace of ideas is misplaced, and of how our thinking about media ownership and diversity might be better served by the metaphor of a mixed media system. 相似文献
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Abstract This article describes a computer program, “Multi‐Map,” designed to introduce experimentation and exploration in the precollege mathematics curriculum. The central activity in MultiMap involves the creation of planar maps which may be applied interactively to graphical objects. The maps may be affine or nonlinear; and (among other activities) they can easily be edited, composed, or applied iteratively. We outline MultiMap's interface and basic functionality, describe a wide variety of exploratory mathematical activities that can be undertaken with the program, and present some observations on the use of MultiMap in the classroom. 相似文献
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Objective
To examine the frequency and predictors of out-of-home placement in a 30-month follow-up for a nationally representative sample of children investigated for a report of maltreatment who remained in their homes following the index child welfare report.Methods
Data came from the National Survey of Child and Adolescent Well-being (NSCAW), a 3-year longitudinal study of 5,501 youth 0-14 years old referred to child welfare agencies for potential maltreatment between 10/1999 and 12/2000. These analyses focused on the children who had not been placed out-of-home at the baseline interview and examined child, family and case characteristics as predictors of subsequent out-of-home placement. Weighted logistic regression models were used to determine which baseline characteristics were related to out-of-home placement in the follow-up.Results
For the total study sample, predictors of placement in the 30-month follow-up period included elevated Conflict Tactics Scale scores, prior history of child welfare involvement, high family risk scores and caseworkers’ assessment of likelihood of re-report without receipt of services. Higher family income was protective. For children without any prior child welfare history (incident cases), younger children, low family income and a high family risk score were strongly related to subsequent placement but receipt of services and case workers’ assessments were not.Conclusions/practice implications
Family risk variables are strongly related to out-of-home placement in a 30-month follow-up, but receipt of child welfare services is not related to further placements. Considering family risk factors and income, 25% of the children who lived in poor families, with high family risk scores, were subsequently placed out-of-home, even among children in families who received child welfare services. Given that relevant evidence-based interventions are available for these families, more widespread tests of their use should be explored to understand whether their use could make a substantial difference in the lives of vulnerable children. 相似文献9.
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Buckley Barbara C. Gobert Janice D. Kindfield Ann C. H. Horwitz Paul Tinker Robert F. Gerlits Bobbi Wilensky Uri Dede Chris Willett John 《Journal of Science Education and Technology》2004,13(1):23-41
This paper describes part of a project called Modeling Across the Curriculum which is a large-scale research study in 15 schools across the United States. The specific data presented and discussed here in this paper is based on BioLogica, a hypermodel, interactive environment for learning genetics, which was implemented in multiple classes in eight high schools. BioLogica activities, data logging, and assessments were refined across this series of implementations. All students took a genetics content knowledge pre- and posttests. Traces of students' actions and responses to computer-based tasks were electronically collected (via a log file function) and systematically analyzed. An intensive 3-day field test involving 24 middle school students served to refine methods and create narrative profiles of students' learning experiences, outcomes, and interactions with BioLogica. We report on one high school implementation and the field test as self-contained studies to document the changes and the outcomes at different phases of development. A discussion of design changes concludes this paper. 相似文献