Query expansion with terms selected using lexical cohesion analysis of documents

We present new methods of query expansion using terms that form lexical cohesive links between the contexts of distinct query terms in documents (i.e., words surrounding the query terms in text). The link-forming terms (link-terms) and short snippets of text surrounding them are evaluated in both interactive and automatic query expansion (QE). We explore the effectiveness of snippets in providing context in interactive query expansion, compare query expansion from snippets vs. whole documents, and query expansion following snippet selection vs. full document relevance judgements. The evaluation, conducted on the HARD track data of TREC 2005, suggests that there are considerable advantages in using link-terms and their surrounding short text snippets in QE compared to terms selected from full-texts of documents.     

Output feedback stabilization for symmetric control systems

This work is devoted to the study of symmetric control systems. It establishes a relation between internal symmetry and external one for a linear invariant control system having n real simple poles. The symmetric stabilization problem is studied using a symmetric feedback gain such that the output control stabilizes the closed-loop system. A necessary and sufficient condition is given to solve this stabilization problem for a symmetric control system (A,B,C) and a generalized symmetric control system (E,A,B,C).     

我国城市用水探讨

针对目前我国城市缺水形势严峻，同时又存在大量浪费水和水污染的现象，再一次敲响了水危机的警钟。本文结合城市用水特点，提出了城市用水、节水的基本原理。城市理想的用水系统应该是一个闭环反馈系统，这一系统应该靠节水和污水回用来实现。文中列举大量数据分析城市节水取0城市水资源系统、闭环反馈系统、工业用水重复利用率     

A relevance feedback mechanism for cluster-based retrieval

Contextual document clustering is a novel approach which uses information theoretic measures to cluster semantically related documents bound together by an implicit set of concepts or themes of narrow specificity. It facilitates cluster-based retrieval by assessing the similarity between a query and the cluster themes’ probability distribution. In this paper, we assess a relevance feedback mechanism, based on query refinement, that modifies the query’s probability distribution using a small number of documents that have been judged relevant to the query. We demonstrate that by providing only one relevance judgment, a performance improvement of 33% was obtained.     

网络舆论中的蝴蝶效应：混沌理论视野的解释

由微内容引起的网络反腐、网络流言、网络造星等＂舆论风暴＂被喻为网络舆论的蝴蝶效应。该概念在学界存在一定程度的异化现象。只有将蝴蝶效应置于混沌学视野的复杂动力学图谱,引入自组织概念,才能避免网络舆论先天不足偏见。研究发现,奇异吸引子触动网络舆论蝴蝶效应的舆论扳机,正反馈集聚引发连锁反应,信息与观点的分形与迭代贯穿其全过程。     

Student perceptions of quality feedback in teacher education

Many reports have identified a perceived lack of quality in regard to assessment feedback in higher education contexts. One research study in 2007 on undergraduate university students found that less than half of the students (46%) collected their formative feedback, suggesting that from their perspective feedback clearly was not fulfilling the role it should. This is a study of 465 graduate students and 101 undergraduate students studying teacher education at a major Australian university. The study investigated what students perceived to be effective, quality feedback based upon their extensive higher education experiences. Students identified preferences in regard to form, detail and timing of assessment feedback. The data were collected by means of pen and paper survey and identified which strategies the students perceived to be the most effective, particularly within the context of large cohort teaching and written assessment formats. Findings agreed with research elsewhere regarding problems with assessment feedback quality and quantity, but students also provided clear indications of how realistic improvements could be made in terms of assessment feedback processes and strategies.     

Investigating university tutor perceptions of assessment feedback: three types of tutor beliefs

Feedback is a key element in effective teaching and learning. The issue of how teachers perceive the role of feedback will impact significantly their feedback approaches, the amount of the detail of their feedback and the time and effort expended on the feedback provision. This research was designed with the purpose of exploring how a group of over 50 tutors who were supporting an online university English course perceived, understood and interpreted the processes of assignment feedback. A factor analysis study based on questionnaire data revealed three sets of tutor beliefs towards assessment and tutor feedback: traditional–autonomous–global (TAG), student‐centred (SC) and traditional‐local (TL). Follow‐up in‐depth interviews were conducted with tutors. The TAG tutors saw scores as the most important feedback to students, but doubted the value of detailed feedback. SC tutors maintained that good tutor feedback should offer more than mere scores, and that students needed feedback in order to improve. TL tutors tended to underline all the errors and provide detailed feedback. They were negative towards the idea of their feedback being monitored. The authors identified some differing and converging tutor perceptions on assessment feedback, the understanding of which could arguably play an important role in introducing changes in tutor feedback culture.     

A proposed methodology for contextualised evaluation in higher education

This paper aims to inspire stakeholders working with quality of higher education (such as members of study boards, study programme directors, curriculum developers and teachers) to critically consider their evaluation methods in relation to a focus on student learning. We argue that many of the existing methods of evaluation in higher education are underpinned by a conception of learning that is de‐contextualised. As a consequence, many data collection methods do not address aspects that affect students’ learning. This is problematic because the core aim of higher education is to facilitate student learning. We propose a contextualised evaluation methodology, guided by 10 key questions, which can help evaluators address concepts and questions of student learning in their evaluations.     

The influence of competences and support on school performance feedback use

Information‐rich environments are created to promote data use in schools for the purpose of self‐evaluation and quality assurance. However, providing feedback does not guarantee that schools will actually put it to use. One of the main stumbling blocks relates to the interpretation and diagnosis of the information. This study examines the relationship between data literacy competences, support given in interpreting the information, actual use of the feedback and potential school improvement effect. A randomised field experiment with 188 school principals from primary education was set up and a post‐test was used to investigate the effects of a support initiative. The results revealed that a minority of schools invested significantly in the interpretation and diagnosis of the school performance feedback (SPF), despite the fact that most of the respondents showed an interest in the SPF report. In addition, data competence support and the subsequent use of feedback were found to be limited.     

普通高校篮球选项课“反馈教学法”实验研究

本文通过随机抽取2009级两个教学班进行一学年的教学实验,来研究探讨反馈教学法应用在普通高校篮球选项课教学中对学生运动技能、理论知识、综合能力等方面的影响以及在教学中的可行性和主要优势。实验结果表明：反馈教学法比传统教学法更有利于提高学生的运动技能、理论知识水平和观察分析解决问题的能力。