How hypertext fosters children’s knowledge acquisition: The roles of text structure and graphical overview

Children in primary and secondary school are asked to go on the Internet for school purposes while research on hypertext has scarcely investigated how children process and learn from hypertext. We therefore examined how hypertext influences children’s knowledge acquisition from expository text. A group of 71 Dutch children (13 years old) from one secondary school for pre-university education participated in the study. In a within-subjects design with four conditions, we compared: regular linear text, regular text with overview, hypertext, and hypertext with overview. Children’s (a) navigation (i.e., reading time and navigation pattern) and (b) learning (i.e., multiple choice knowledge questions and mind maps) was measured. Although reading times did not differ, the children navigated less linearly in both hypertext conditions than in the regular text with overview condition. The four types of text led to the same deep understanding as measured on the text base level. Analyses of the mind maps, however, showed the children to construct richer situation models after reading hypertext or hypertext with an overview relative to regular linear text and regular text with overview. We therefore conclude that hypertext fosters a deeper level of information processing when appropriately designed relative to regular linear text.     

Text complexity of open educational resources in Portuguese: mixing written and spoken registers in a multi-task approach

Language Resources and Evaluation - This paper presents a study on text complexity of Open Educational Resources (OER) in Brazilian Portuguese. In a data analysis of the Brazilian Ministry of...     

Classifying and Formally Verifying Integer Constant Folding

Constant folding is a well-known optimization of compilers which evaluates constant expressions already at compile time. Constant folding is valid only if the results computed by the compiler are exactly the same as the results which would be computed at run-time by the target machine arithmetic. We classify different arithmetics by deriving a general condition under which a target-machine arithmetic can be replaced by a compiler arithmetic. Furthermore, we consider integer arithmetics as a special case. They can be described by residue class arithmetics. We show that these arithmetics form a lattice. Using the order relation in this lattice, we establish a necessary and sufficient criterion under which constant folding can be done in a residue class arithmetic that is different from the one of the target machine. Concerning formal verification, we have formalized our proofs in the Isabelle/HOL system. As examples, we discuss the Java and C integer arithmetics and show which compiler arithmetics are valid for constant folding. This discussion reveals also potential sources of incorrect behavior of C compilers.     

Smart Citizens: Exploring the Tools of the Urban Bottom-Up Movement

As web technology and (big) data continue to transform how we organize ourselves, scholarly research increasingly zooms in on the socio-material conditions of citizen participation and public engagement, the objects and devices that organize publics. Where social issues may often be the driver of such public engagement, increasingly the city and, more specifically, the neighborhood itself have become a central objects connecting their inhabitants through online networks and neighborhood events. Tools and apps for citizen participation then weave together neighborhood stakeholders (e.g. inhabitants, municipal parties and entrepreneurs). This paper zooms in on a sample of 40 such tools that enable and organize bottom-up citizen participation in the city of Amsterdam. Combining a theoretical framework with content analysis, digital methods and data visualization, this paper marks the starting point of a longitudinal analysis of online tools for the urban bottom-up movement.     

Grundrechtsschutz im Europa des Lissaboner Vertrags

Nachdem als letzter Mitgliedstaat der Europ?ischen Union auch Tschechien im November 2009 den Lissaboner Vertrag ratifiziert hatte, konnte das Vertragswerk¹ zum 01. Dezember 2009 in Kraft treten. Seither sind allerdings die mit der neuen Rechtsgrundlage der Europ?ischen Union verbundenen vielf?ltigen Wirkungen kaum ins Bewusstsein der europ?ischen ?ffentlichkeit gelangt. Sie werden von den globalen Banken- und Wirtschaftsproblemen sowie von der aktuellen Krise der europ?ischen W?hrungsunion überlagert, die die nationalen Politiken der EU-Mitgliedstaaten und die gemeinschaftliche europ:aische Politik vor gro?e Herausforderungen stellen und deren Aufmerksamkeit in hohem Ma?e in Anspruch nehmen. Es mag also noch dauern, bis Europa in absehbarer Zeit und hoffentlich ohne an seinen politischkonstitutiven Fundamenten Schaden zu nehmen die aktuellen Krisen überwunden haben wird. Erst dann dürfte den Bürgerinnen und Bürgern Europas deutlicher werden, dass mit dem Inkrafttreten des Vertrages von Lissabon eine unter mehreren Gesichtspunkten neue Epoche des Europ?ischen Integrationsprozesses begonnen hat. Das gilt nicht nur, aber vor allem für die Innen- und Rechtspolitik — für jene Bereiche europ?ischer Politik also, die die Herstellung des seit 1999 im Amsterdamer Vertrag avisierten „Raumes der Freiheit, der Sicherheit und des Rechts“ zum Ziel haben. Innerhalb dieser im hohen Ma?e grundrechtssensiblen Politikfelder wird die neue Epoche vor allem von erheblichen Ver?nderungen sowohl im materiellen, rechtlichen als auch im institutionellen, gerichtlichen Schutz der Grund- und Freiheitsrechte der europ?ischen Bürgerinnen und Bürger gepr?gt sein.     

Don't underestimate the problems of user centredness in software development projectsthere are many!

. On the basis of a longitudinal field study of 29 commercial software development projects, the pros and cons of user centredness in software development were analysed. We looked at two concepts: user participation-an organizational device-involving a user representative in the team, and user orientation-a cognitive-emotional concept-which pertains to positive attitudes towards users. Both were found to be associated with project difficulties relating to process and product quality as well as overall project success. We suggest that the issue is no longer whether or not to involve users, but instead to develop a realistic understanding of the difficulties associated with user centredness.