Verteilte Metadatenverwaltung und Anfragebearbeitung für Internet-Datenquellen     

Markus Keidl  Alfons Kemper  Donald Kossmann  Alexander Kreutz 《Informatik - Forschung und Entwicklung》2002,10(1):123-134

Wir pr?sentieren in dieser Arbeit das ObjectGlobe-System, ein offenes und verteiltes Anfragebearbeitungssystem auf Internet-Datenquellen. ObjectGlobe erweitert die begrenzten F?higkeiten des Internets bezüglich Anfragebearbeitung, indem es einen offenen Marktplatz schafft, in dem eine Vielzahl von Anbietern Rechenzeit, Daten und Anfrageoperatoren bereitstellen. Den Schwerpunkt dieses Beitrags bildet die im Rahmen des ObjectGlobe-Projekts entwickelte Metadatenverwaltung MDV, ein verteiltes Metadaten-Management-System. Es besitzt eine 3-schichtige Architektur und unterstützt Caching und Replikation in der Mittelschicht, so dass Anfragen lokal ausgewertet werden k?nnen. Benutzer spezifizieren die Informationen, die sie ben?tigen und die repliziert werden, mit Hilfe einer besonderen Regelsprache. Um Replikate aktuell zu halten und die Replikation von neuen und relevanten Informationen anzusto?en, verwendet das MDV-System einen neuartigen Publish & Subscribe-Algorithmus. Wir beschreiben diesen Algorithmus im Detail und zeigen, wie er mit Hilfe eines normalen relationalen Datenbanksystems implementiert werden kann.  相似文献   

ASSESSING STUDENTS’ EXPERIMENTATION PROCESSES IN <Emphasis Type="Italic">GUIDED INQUIRY</Emphasis>     

Markus Emden  Elke Sumfleth 《International Journal of Science and Mathematics Education》2016,14(1):29-54

In recent science education, experimentation features ever more strongly as a method of inquiry in science classes rather than as a means to illustrate phenomena. Ideas and materials to teach inquiry abound. Yet, tools for assessing students’ achievement in their processes of experimentation are lacking. The present study assumes a basal, non-exclusive process model of inquiry in experimentation that can be considered a consensus from multiple approaches: (1) finding an idea/hypothesis, (2) planning and conducting an experiment, and (3) drawing conclusions from evidence. The study confronted 339 secondary level students with three guided inquiry experimentation tasks on 3 days. Selected working groups were videotaped while experimenting. All the students reported their processes in a structured report form simultaneous to their progress. The generated videos and reports were analysed in a two-stepped way: (1) Experimentation was coded according to the process model into process plots; on basis of these, (2) process-focused performance scores were calculated considering logical coherence and immediacy of the inquiry processes. Correlative analyses show for two of the tasks that the report format yielded comparable performance scores to those generated from video data after students have had opportunity to learn the surveying formats (r _S?>?.80). A first suggestion of a process-oriented assessment tool for inquiry in experimentation can be drawn from this study. It might be used to inform and complement secondary science instruction.  相似文献   

The Adequacy of Privacy: The European Union Data Protection Directive and the North American Response     

Colin J. Bennett Charles  D. Raab 《The Information Society》1997,13(3):245-264

The recently passed European Directive on the Protection of Personal Data aims to harmonize European data protection law at a higher level of protection than exists now. It represents a European consensus on a standard for personal privacy and a model for countries without data protection laws. The protracted process for agreement and ratification, however, has produced a document with many derogations and ambiguities, reflecting the wider moves towards 'subsidiarity' within the European Union. Of concern to North America is the stipulation that transborder data flow may not be permitted unless the receiving country can demonstrate an 'adequate' level of protection. While the process through which this provision will be interpreted and applied is so far found to be complicated and unclear, nevertheless European authorities will be reluctant to tolerate 'data havens,' a fact that should concern North American business that relies on the unimpeded flows of personal data from and to Europe. Neither Canada nor the United States can claim 'adequate' data protection according to the European standard. However, Canadian efforts through the Canadian Standards Association and the Federal Information Highway Advisory Council signal an attempt to fashion a more comprehensive policy framework for privacy than the more incremental and reactive approach of the United States. This divergence is explained by key cultural, economic, and political factors within Canada, which have caused a different reaction to the extraterritorial effects of the European Union's Data Protection Directive.  相似文献   

Undisclosed desires: quality managers’ normative notions regarding the implementation of quality management     

Markus Seyfried 《Assessment & Evaluation in Higher Education》2019,44(7):1106-1119

Following decades of quality management featuring in higher education settings, questions regarding its implementation, impact and outcomes remain. Indeed, leaving aside anecdotal case studies and value-laden documentaries of best practice, current research still knows very little about the implementation of quality management in teaching and learning within higher education institutions. Referring to data collected from German higher education institutions in which a quality management department or functional equivalent was present, this article theorises and provides evidence for the supposition that the implementation of quality management follows two implicit logics. Specifically, it tends either towards the logic of appropriateness or, contrastingly, towards the logic of consequentialism. This study’s results also suggest that quality managers’ socialisation is related to these logics and that it influences their views on quality management in teaching and learning.  相似文献   

Teacher humor: longitudinal effects on students’ emotions     

Bieg  Sonja  Grassinger  Robert  Dresel  Markus 《European Journal of Psychology of Education - EJPE》2019,34(3):517-534

European Journal of Psychology of Education - Characteristics of teaching are associated with the emotions students experience in the classroom; however, empirical evidence regarding longitudinal...  相似文献   

STUDENTS’ WAYS OF REASONING ABOUT NONLINEAR FUNCTIONS IN GUESS-MY-RULE GAMES     

John M. Francisco  Markus H?hki?niemi 《International Journal of Science and Mathematics Education》2012,10(5):1001-1021

There is a growing movement toward the introduction of algebra in early grades. This is supported by an increasing number of research studies that have reported success in getting young students to “do” mathematics considered beyond their reach. Yet, the consensus is that more research is needed to provide insights into the processes by which students make sense of algebraic ideas. In particular, more studies are needed on how nonlinear functions can be introduced in early grades. This article reports an algebra research strand that introduced seventh grade students to quadratic functions using Guess-My-Rule games. The article describes several instances of the students engaging successfully with ideas and forms of reasoning involving quadratic functions. The purpose is to contribute to the debate on the introduction of algebra in early grades by providing further evidence of young students’ ability to engage with algebraic ideas usually considered to be beyond their reach.  相似文献   

Active ingredients and factors for deep processing during an example-based training intervention     

Hefter  Markus H.  Berthold  Kirsten 《Learning Environments Research》2022,25(1):17-39

Learning Environments Research - In two experiments with German secondary school students (N1 = 43; N2 = 41), we aimed to analyze and optimize an effective learning...  相似文献   

Confidence in performance judgment accuracy: the unskilled and unaware effect revisited     

Marion Händel  Markus Dresel 《Metacognition and Learning》2018,13(3):265-285

Since its introduction in the late 1990s, the unskilled and unaware effect motivated several further studies. As it stands, low-performing students are assumed to provide inaccurate and overconfident performance judgments. However, as research with second-order judgments (SOJs) indicates, they apparently have some metacognitive awareness of this. The current study with 266 undergraduate students aimed to provide in-depth insights into both the reasons for (in)accurate performance judgments and the appropriateness of SOJs. We implemented a general linear mixed model (GLMM) approach to study item-specific performance judgments in the domain of mathematics at the person and item level. The analyses replicated the well-known effects. However, the GLMM analyses revealed that low-performing students’ lower confidence apparently did not indicate subjective awareness, given that these students made inappropriate SOJs (lower confidence in accurate than in inaccurate judgments). In addition, students’ self-generated explanations for their judgements indicated that low-performing students have difficulties recognizing that they possess topic knowledge to solve an item, whereas high-performing students struggle with admitting that they do not know the answer to a question. In sum, our results indicate that students at all performance levels have some metacognitive weaknesses, which, however, occur subject to different judgment accuracy.  相似文献   

Integrating ‘Outer Space Design’ into Design Curriculum     

Markus Wilsing  Nil Akpinar‐Wilsing 《The International Journal of Art & Design Education》2004,23(1):73-80

The imagination of human beings and the exploration of novel ideas have always contributed to developments in science. These developments lead us to re‐examine the existing structures in our environment and society so that they can be further improved. The review of literature regarding science fiction and its place in education also highlights the need for novel topics in design education. Thus, integrating a course in the curriculum of design education that aims to explore futuristic and visionary oriented environments like Mars Colonies, Orbital Space Colonies or Orbital Space Hotels would seem crucial. Such topics would probably not only stimulate the students in their design process, but also develop their imagination, as they require research and synectic thinking. As to whether stimulating imagination should be among the priorities in teaching, in fact, it is the dreams, imagination and creativity that has shaped and will shape human development and social‐cultural contexts.  相似文献   

Alternative vocabularies in the test validity literature     

Keith A. Markus 《Assessment in Education: Principles, Policy & Practice》2016,23(2):252-267

Justification of testing practice involves moving from one state of knowledge about the test to another. Theories of test validity can (a) focus on the beginning of the process, (b) focus on the end or (c) encompass the entire process. Analyses of four case studies test and illustrate three claims: (a) restrictions on validity entail a supplement required to obtain justification from validity. (b) Rationales for restrictions assume particular contexts. (c) Claims can be translated between contrasting vocabularies. Implications for consumers of test validity theory include encouragement to focus on content instead of form and to write and read mindfully of the multiplicity of validity vocabularies. Implications for producers of test validity theory include encouragement to consider multiple reconstructions of a particular theory of test validity, clearly distinguish validity theories from validity definitions, and focus on contributing arguments that constrain possible theories rather than contributing definitions or broad frameworks.  相似文献