建造更快互联网

1 东京的指挥家挥动指挥棒,美国克利夫兰市的管弦乐队开始演奏.当指挥家挥动几下指挥棒后,位于柏林的小提琴家也加入演奏行列.为了补偿传输时间上的延迟,音乐家们随着电子节拍器一齐演奏.这场表演由高保真扬声器和高清晰度电视播放.这样的音乐表演实验对电视网络来说已经足够具有挑战性了,而在因特网上,目前还不可能实现.……     

Self-regulated strategy development in writing: Going beyond NLEs to a more balanced approach

In this article, we present an argument for consideration by those researching and promoting new learning environments (NLEs). We believe advocates of NLEs should consider the literature and research base indicating effective instruction is not based on a forced dichotomy between theoretical perspectives, but rather a thoughtful, pragmatic blending of practices based on evidence gained from various perspectives and lines of research. While unguided or minimally guided instructional approaches are popular and intuitively appealing, these approaches ignore substantial evidence indicating these approaches are less effective and less efficient than instructional approaches that incorporate guidance of the learning process that is faded as internal guidance is developed (Kirschner et al., Educ Psychol 41:75–86, 2006). We illustrate how integrating evidence from multiple theoretical perspectives leads to the development of more powerful approaches to learning and instruction through a review of the premises, evolution, and research behind Self-Regulated Strategy Development (SRSD) in the area of writing.     

Assessment for learning: a case study using feedback effectively in an essay‐style test

Strategic and well‐planned use of feedback in the assessment process is key to promoting learning. This paper evaluates the role a two‐stage test process played in guiding and assisting student learning in a second‐year module at the University of KwaZulu‐Natal, South Africa. Having been provided with verbal and written feedback without grades from the first test, students were given the opportunity to write a different, second test, and each was required to choose which one was graded. Students were generally very positive about the assessment process, most participated willingly and fully, many learned differently for the second test, and there was evidence of meta‐cognitive awareness and understanding. Despite this, a number of students experienced difficulty and frustration in judging the quality of their work. The discussion focuses on process and learning issues, on the utility of feedback and on formative test assessment procedures.     

Gender roles and the American academe: a case study of graduate student mothers

Studies have found that motherhood is significantly associated with attrition for female graduate students in the United States. Few, however, have examined this phenomenon from the point of view of current students. Utilizing data from 30 in‐depth interviews with student mothers from a number of academic fields, this study details both the structural environments and the socio‐cultural constructs that affect the women’s daily experiences. The data highlight the fact that the symbolic nature of both roles – mother and student – is often in conflict with the structural elements around which each role is performed. Student mothers confront this dilemma through a number of strategic practices including ‘maternal invisibility’, ‘academic invisibility’, luck, and reliance on the more traditional means of economic and emotional support that come from spouses and parents. In detailing these practices, the study offers both important clues about the factors that may contribute to attrition for graduate student mothers as well as suggestions for institutional improvement.     

丹尼的礼物

一份饱含真情的圣诞节礼物,虽然在金钱上非常微薄,却让班主任感动得热泪盈眶,久久不能忘怀。丹尼的礼物可谓是"礼轻情意重"。     

Best entry points for structured document retrieval—Part II: Types,usage and effectiveness

Structured document retrieval makes use of document components as the basis of the retrieval process, rather than complete documents. The inherent relationships between these components make it vital to support users’ natural browsing behaviour in order to offer effective and efficient access to structured documents. This paper examines the concept of best entry points, which are document components from which the user can browse to obtain optimal access to relevant document components. It investigates at the types of best entry points in structured document retrieval, and their usage and effectiveness in real information search tasks.     

The exact-display approach for online catalog subject searching

When public catalog users enter queries that exactly match the catalog's controlled vocabulary, online systems should respond with browsing lists of alphabetically arranged subject headings, because such displays guide users to retrievals based on the assignment of the matched subject headings to bibliographic records. Unfortunately, studies of online catalog searching demonstrate that alphabetical displays are no longer capable of managing large numbers of subdivided forms of subject headings, because searchers exhibit low levels of perseverance when faced with large numbers of retrievals. This paper introduces a new approach to displaying retrieved subject headings in subject searching—the exact-display approach—designed to encourage users to browse bibliographic information. The purpose of this paper is to emphasize the importance of the exact-display approach by showing how many user queries would be candidates for this approach, demonstrate an implementation of the exact-display approach in an experimental online catalog, and feature end-user experiences with this approach as implemented in the experimental catalog. End-user experiences gave the authors the opportunity to make several recommendations for enhancing the original design of the exact-display approach so that future implementations of this approach in operational online catalogs are responsive to the needs of online catalog users.     

Interventions for reading difficulties: a comparison of response to intervention by ELL and EFL struggling readers

This article explores whether struggling readers from different primary language backgrounds differ in response to phonologically based remediation. Following random assignment to one of three reading interventions or to a special education reading control program, reading and reading-related outcomes of 166 struggling readers were assessed before, during, and following 105 intervention hours. Struggling readers met criteria for reading disability, were below average in oral language and verbal skills, and varied in English as a first language (EFL) versus English-language learner (ELL) status. The research-based interventions proved superior to the special education control on both reading outcomes and rate of growth. No differences were revealed for children of EFL or ELL status in intervention outcomes or growth during intervention. Oral language abilities at entry were highly predictive of final outcomes and of reading growth during intervention, with greater language impairment being associated with greater growth.