What goes before the CART? Introducing classification trees with Arbor and CODAP     

Tim Erickson  Joachim Engel 《Teaching Statistics》2023,45(Z1):S104-S113

This volume is largely about nontraditional data; this paper is about a nontraditional visualization: classification trees. Using trees with data will be new to many students, so rather than beginning with a computer algorithm that produces optimal trees, we suggest that students first construct their own trees, one node at a time, to explore how they work, and how well. This build-it-yourself process is more transparent than using algorithms such as CART; we believe it will help students not only understand the fundamentals of trees, but also better understand tree-building algorithms when they do encounter them. And because classification is an important task in machine learning, a good foundation in trees can prepare students to better understand that emerging and important field. We also describe a free online tool—Arbor—that students can use to do this, and note some implications for instruction.  相似文献   

The emergence of openness: How and why firms adopt selective revealing in open innovation     

Joachim Henkel  Simone Schöberl  Oliver Alexy 《Research Policy》2014

Open innovation is often facilitated by strong intellectual property rights (IPRs), but it may also function, and even be boosted, when firms deliberately waive some of their IPRs. Extant literature has pointed out the potential benefits of such behavior, but falls short of explaining what triggers firms to practice it in the first place and to maintain or extend it. Since the waiving of IPRs runs counter to common views on strategy and competition and to engrained practices, this is a non-trivial question. To address it, we conduct an empirical study in a segment of the computer component industry which traditionally has taken a rather proprietary stance. With the advent of the open source operating system Linux, firms increasingly waived their IPRs on software drivers. We trace and analyze this process using both qualitative and quantitative methods. Our results indicate that component makers went through a learning process, which led some to realize how selectively waiving IPRs may be beneficial for their business. We uncover customer demand pull as the initial trigger and observe how a positive feedback loop sets in subsequently, leading to a further increase in the use of selective revealing. Overall, we find that openness develops into a new dimension of competition. We discuss the implication of our findings for research on open innovation and highlight how they impact managers in practice.  相似文献   

Increasing Student Involvement in Cognitive Aging Research     

Linda A. Henkel 《Educational gerontology》2013,39(7):505-516

The involvement of undergraduates in research on aging has benefits for the students and for the faculty mentors, as well as for their departments, their universities, and the field of gerontology at large. This article reports on the application of a 3-year Academic Research Enhancement Award (AREA) by the National Institute on Aging awarded to Fairfield University—a selective, midsize private Jesuit institution—to increase undergraduate involvement in cognitive aging research. The series of studies examines age-related differences in veridical and false memories arising from repeated attempts to remember information. The grant has greatly expanded the research opportunities available for undergraduates, and has provided research training to a greater number and broader range of students than was previously possible (over the 3-year period, over 30 students gained hands-on, in depth research training). Specific student research activities on the Fairfield Cognitive Aging Project are discussed, and the development of a course on supervised research, its place in the curriculum, and the immediate and long-term benefits to students are described.  相似文献   

Enhancing scientific discovery learning through metacognitive support     

Josef Künsting  Julian Kempf  Joachim Wirth 《Contemporary educational psychology》2013

Using a virtual physics lab, we analyzed the impact of metacognitive support on simulation-based scientific discovery learning (SDL). The dependent variables for learning outcome were the immediate conceptual knowledge gain and the retained conceptual knowledge three weeks later. Additional dependent variables were the actual use of a domain-specific cognitive strategy, motivation, emotions, and cognitive load. To contrast the effects of metacognitive support with possible effects of goal specificity, the experimental study followed a 2 × 2 design with a sample of N = 129 ninth grade students and with metacognitive support (yes vs. no) and learning goals (specific vs. nonspecific) as factors. The results showed positive effects of metacognitive support on learning outcome, on actual cognitive strategy use, and on learning emotions. No interaction effect of metacognitive support and goal specificity on learning outcome was observed.  相似文献   

体育项目中的训练与过度训练特征   总被引：4，自引：0，他引：4  

Ulrich Hartmann  Joachim Mester  陈小平 《体育科研》2006,27(1):44-49

目的:多种症状都支持对过度训练(OT)的探查。测量血清尿素(SU)和血清肌氨酸激酶(CK)值,除了对优秀运动员进行诊断和分析之外,也用于对运动员日常训练状态进行监控。因此,我们将根据不同运动员,同一运动员的不同状态,对这些指标的意义进行检验。方法:测试时象为具有国际水平的赛艇运动员,所有数据均来自于对这些运动员训练过程的测试。结果:6981例血清尿素测试样本(男运动员717人,女运动员285人)表明, 数据呈现出一种轻微不对称的正态分布态势(男运动员80％,5～7mmol·L-1;女运动员75％, 4～6mmol·L-1)。女运动员的数值比男运动员约低1．5mmol·L-1,个体差异较大,因此以 8．3mmol·L-1(男运动员)和7．0mmol·L-1(女运动员)作为判断运动员过度训练的固定阈值是不可靠的。在运动训练中,肌氨酸激酶(CK)也已被作为判定肌肉紧张的重要参数进行检测和评价。2790例肌氨酸激酶测试样本(男运动员497人,女运动员350人)显示,数据的频率分布为不对称的正态分布,在100—250U·L-1的区域内具有明显偏向高值区域的趋势,在250～ 350U·L-1和1000～2000U·L-1范围内分布频数明显升高。男运动员的最高值为3000U·L- 1,女运动员最高值为1150U·L-1,个体差异显著。血清肌氨酸激酶水平长期较低的运动员显示出小的数值变化;血清肌氨酸激酶水平长期较高的运动员在数值上显示出显著的变化波动。结论:这两个参数也许都有助于从大量样本中测定个人数值基准线。对这两个参数的测量至少应该在标准条件下每3天进行一次。如果在一段时间的训练(2—4天)后同时观察到参数数值显著升高和训练耐受力降低,则表明机体的分解／合成代谢活动或训练耐受力不足的可能性升高。  相似文献   

Fundamentals of Orthodox Culture (FOC): a new subject in Russia’s schools     

Joachim Willems 《British Journal of Religious Education》2007,29(3):229-243

The question of religious education is one of the most controversial questions in the current discussions on religion and politics in Russia. Most notably a new subject, Fundamentals of Orthodox Culture (FOC), is of interest because it differs markedly from Western European approaches to religious education. Referring to ‘Culturology’ FOC combines an introduction into Russian culture and patriotism with moral education and the imparting of knowledge about Orthodox Christianity. According to its own self‐image FOC is a non‐denominational subject, but an analysis of two widespread textbooks will be used to show that FOC is, in all respects, Orthodox.  相似文献   

Open access — the rise and fall of a community‐driven model of scientific communication          下载免费PDF全文

Joachim SCHÖPFEL 《Learned Publishing》2015,28(4):321-325

• In 25 years, open access has become a significant part of scientific communication, but its success story should not conceal a fundamental change of its nature.
• Open access started at the grassroots, as a bottom‐up, community‐driven model of open journals and repositories but today the driving forces are commercial, institutional, and political interests.
• The fall of open access as a community‐driven model is running the risk of becoming dysfunctional for scientists and may create new barriers and digital divides.

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Editors' Note     

Beat F. Schmid  Peter Glotz  Joachim Haes  Bozena I. Mierzejewska  Yingzi Xu 《媒体管理杂志》2013,15(1-2)

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Editors' Note     

Beat F. Schmid  Peter Glotz  Joachim Haes  Bozena I. Mierzejewska  Yingzi Xu 《媒体管理杂志》2013,15(3-4):101-102

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Book reviews     

George F. Kneller  Renate Nestvogel  Jean-Pierre Jallade  Volker Lenhart  Gabriel Carron  J. R. Liesch  W. D. Wall  Jürgen Schriewer  Dale C. Paul  William J. Platt  Joachim Köhler  T. Neville Postlethwaite  D. La Verne Buckley 《International Review of Education/Internationale Zeitschrift für Erziehungswissenschaft/Revue internationale l'éducation》1978,24(1):81-106

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