Biology Teachers Designing Context-Based Lessons for Their Classroom Practice—The importance of rules-of-thumb

In science education in the Netherlands new, context‐based, curricula are being developed. As in any innovation, the outcome will largely depend on the teachers who design and implement lessons. Central to the study presented here is the idea that teachers, when designing lessons, use rules‐of‐thumb: notions of what a lesson should look like if certain classroom outcomes are to be reached. Our study aimed at (1) identifying the rules‐of‐thumb biology teachers use when designing context‐based lessons for their own classroom practice, and (2) assessing how these personal rules‐of‐thumb relate to formal innovative goals and lesson characteristics. Six biology teachers with varying backgrounds designed and implemented a lesson or series of lessons for their own practice, while thinking aloud. We interviewed the teachers and observed their lessons. Our results suggest that rules‐of‐thumb, which differed substantially among the teachers, indeed to a great extent guide the decisions teachers make when designing (innovative) lessons. These rules‐of‐thumb were often strongly associated with intended lesson outcomes. Also, teachers’ personal rules‐of‐thumb were more powerful in determining the lesson design than formal innovative goals and lesson characteristics. The results of this study encourage more research into how rules‐of‐thumb reflect teachers’ practical knowledge, for which suggestions are made.     

Relational Framing Theory: Utterance Form and Relational Context as Antecedents of Frame Salience

Using relational framing theory, this article examines the influence of utterance type and relational context on the salience of relational frames. The authors report the results of two studies that used scenarios to manipulate utterance form and information about the relationship between interactants. Participants rated the relevance of dominance-submissiveness and affiliation-disaffiliation frames to interpreting the hypothetical interactions. Results showed that judgments of dominance-submissiveness frame salience were sensitive to variations in utterance type and relational context, but the results were mixed for the affiliation-disaffiliation frame. The authors discuss the implications for relational framing theory and the possibility of an affiliation bias.     

数据库细粒度访问控制技术应用研究

讨论了数据库细粒度访问控制的几种常见技术,并结合实例介绍了如何使用VPD、应用上下文和视图来构建企业细粒度访问控制体系。经实践证明,该体系可有效增强数据库安全性。     

Using genetic algorithms to evolve a population of topical queries

Systems for searching the Web based on thematic contexts can be built on top of a conventional search engine and benefit from the huge amount of content as well as from the functionality available through the search engine interface. The quality of the material collected by such systems is highly dependant on the vocabulary used to generate the search queries. In this scenario, selecting good query terms can be seen as an optimization problem where the objective function to be optimized is based on the effectiveness of a query to retrieve relevant material. Some characteristics of this optimization problem are: (1) the high-dimensionality of the search space, where candidate solutions are queries and each term corresponds to a different dimension, (2) the existence of acceptable suboptimal solutions, (3) the possibility of finding multiple solutions, and in many cases (4) the quest for novelty. This article describes optimization techniques based on Genetic Algorithms to evolve “good query terms” in the context of a given topic. The proposed techniques place emphasis on searching for novel material that is related to the search context. We discuss the use of a mutation pool to allow the generation of queries with new terms, study the effect of different mutation rates on the exploration of query-space, and discuss the use of a especially developed fitness function that favors the construction of queries containing novel but related terms.     

英语插入语的交际语境顺应性研究

在对存在于各种语体中的插入语研究进行回顾和总结的基础上,尝试采用Verschueren的顺应理论(Theory of Adaptation)分析在言语交际插入语的使用和交际语境之间的关系.通过具体分析,指出插入语的使用是人们顺应交际语境的结果.     

科技英语的文体特征

科技英语作为一种功能语体是在普通英语的基础上发展起来的。因而无论在词汇方面,还是在语法方面,它同基础英语没有绝对的界限。但是在语言发展的长期过程中,其独特的活动形式使之在语言方面形成了许多其他语言变体所没有的特点。采用现代文体学理论,从字位、词汇、句法/语法、语境四个层面对科技英语的文体特征进行分析,定会对科技英语的阅读理解,写作与翻译提供某些启示,对进一步推广和发展科技英语具有十分重大的意义。