Examining the effectiveness of real-time query expansion

Interactive query expansion (IQE) (c.f. [Efthimiadis, E. N. (1996). Query expansion. Annual Review of Information Systems and Technology, 31, 121–187]) is a potentially useful technique to help searchers formulate improved query statements, and ultimately retrieve better search results. However, IQE is seldom used in operational settings. Two possible explanations for this are that IQE is generally not integrated into searchers’ established information-seeking behaviors (e.g., examining lists of documents), and it may not be offered at a time in the search when it is needed most (i.e., during the initial query formulation). These challenges can be addressed by coupling IQE more closely with familiar search activities, rather than as a separate functionality that searchers must learn. In this article we introduce and evaluate a variant of IQE known as Real-Time Query Expansion (RTQE). As a searcher enters their query in a text box at the interface, RTQE provides a list of suggested additional query terms, in effect offering query expansion options while the query is formulated. To investigate how the technique is used – and when it may be useful – we conducted a user study comparing three search interfaces: a baseline interface with no query expansion support; an interface that provides expansion options during query entry, and a third interface that provides options after queries have been submitted to a search system. The results show that offering RTQE leads to better quality initial queries, more engagement in the search, and an increase in the uptake of query expansion. However, the results also imply that care must be taken when implementing RTQE interactively. Our findings have broad implications for how IQE should be offered, and form part of our research on the development of techniques to support the increased use of query expansion.     

On the optimality of hysteresis operators in signal processing and communication systems

This paper demonstrates that hysteresis operators are the optimal estimators for a large class of estimation and decision problems. This class of problems arises whenever a cost is associated with actions needed to process changes in the estimates or decisions. A simple example related to least-squares estimation is used to illustrate and motivate the developments in this paper. Subsequently, the problem of mean-square estimation with minimal cost of actions is investigated. These results provide a justification for the use of hysteresis in many practical signal processing and communication applications.     

踢自己的屁股

有一位业余发明家是美国独创性天才的象征,他曾经发明了复印机和可植入人体的心脏起搏器.美国专利商标局批准的每五项专利就有一项出自他手,然而,这位老兄更多时候不像是托马斯·爱迪生,倒像是一位爱小题大做的人.     

Learner control of context and instructional support in learning elementary school mathematics

Learner-control strategies for selecting problem context and the level of instructional support were examined separately and in combination on a computer-based mathematics unit on the metric system. Subjects were 240 sixth-grade students assigned to 15 treatments formed by crossing five context conditions (animals, sports, clothing, nocontext, and learner control) with three instructional support conditions (minimum, maximum, and learner control). As hypothesized, comparisons of instructional support conditions on posttest achievement showed performance to be lowest under learner control. Subjects opted to view very few items and to decrease the amount they selected over the course of the instruction. No effects were associated with the context variable, although on one of the three lessons, learner-control subjects made significantly fewer on-task errors than did no-context subjects. Further analyses showed a strong tendency by learner-control context subjects to vary their selection of contexts across lessons. Subjects in the context and instructional support learner-control strategies indicated positive attitudes toward the strategies.     

Uses and effects of learner control of context and instructional support in computer-based instruction

The present study examines uses and effects of learner-control of the context or theme of practice examples on a statistics lesson in combination with learner control of the number of examples examined. Subjects were 227 undergraduate students assigned to 15 treatments formed by crossing five context conditions (learner control, education, business, sports, no-context) with three instructional support conditions (learner-control, maximum, minimum). No differences in achievement were attained as a function of either treatment variable. Findings showed, however, that learners who received preferred contexts (i.e., learner-control-context subjects) selected a greater number of examples than those who received prescribed contexts. In addition, achievement was positively related to the frequency with which subjects varied the number of examples selected across lessons. Despite the absence of achievement benefits, the learner-control-context strategy elicited highly favorable student reactions as a learning orientation.     

A Level Revamped: English Literature,the Universities and the Schools

This paper examines current developments in A Level English Literature in the context of a long‐running debate about the role of context and interpretation in the course, and explores the influence of university English on this debate. Following discussion of developments around Curriculum 2000, I trace the debate back to the ‘theory wars’ of the 1970s and 1980s, examining the influence of voices from universities on discourses about the nature of literary study at A Level, and drawing out tensions within the secondary community among traditionalists, liberals and radicals. I suggest that there is now a strong move to bring A Level Literature closer to university English, and link this with similar movements in Australia and the US, where sympathetic curricula and pedagogies, underpinned by critical theory, have been developed.     

Intellective Functioning and Strategy Use in Children with Insulin-dependent Diabetes Mellitus

The cognitive development of children with either early or late onset insulin-dependent diabetes mellitus (IDDM) was investigated with tasks measuring intellectual ability, memory, and academic progress. In addition, children's perceptions of their competence and parents' perspectives on family functioning and their children's behavior were compared. It was found that children with IDDM scored within the normal range on standardized measures of intelligence and academic performance but evidenced some school difficulties, as reflected in subscale performance as well as in their need of remedial education services. Further, evidence was found to suggest deficiencies in children's use of strategies to organize and recall information, particularly for those with early onset of disease. Children's perceived self-competencies and parents' reports of family functioning were strikingly similar across groups. However, parents of those children whose illness began prior to age 5 reported their children to have poor attention spans and difficulty completing tasks.     

A Comparison of Existing School Counselor Program Content With The Education Trust Initiatives

In a national survey of entry‐level school counselor preparation programs, counselor educators were asked about the extent to which they addressed, in their classes, concepts defined by The Education Trust literature and the extent to which these concepts were important in preparing school counselors. The relationship between existing programs and The Education Trust initiatives for the preparation of school counselors is discussed.     

Assessment of Knowledge and Behavior Change of a High School Positive Deviance Food Safety Curriculum

High school students are a critical audience for food safety. Students may enter the foodservice industry or become primary meal preparers for their families. The positive deviance food safety curriculum was developed based on the messages from the Fight BAC! Campaign. The curriculum is designed for high school students to overcome barriers to safe food handling practices. This study evaluated the effectiveness of the positive deviance approach to change food safety knowledge and behaviors among high school students. Students (n = 218) from two high schools participated in this study. The positive deviance method uses group discussions lead by the teacher who reinforces and praises behaviors, which reflect recommended food handling practices. Measurements included pre‐ and postsurveys, preobservations and postobservation cooking classes, take‐home tasks, and in‐class activities. Results indicated that the curriculum significantly increased students’ food safety knowledge. Specifically, the percentage of students believing that color was a good indicator of meat doneness dropped from 52% to 17% after exposure to the curriculum. When observed, the students’ compliance with recommended behaviors increased. Prior to instruction, most ground beef burgers students cooked did not reach 160°F, while after the intervention, almost all of the burgers reached 160°F or higher. The curriculum will benefit from a revision that emphasizes areas such as how to use, calibrate, and to clean food thermometers.     

海外收购与消化不良

为扩大知名度、追逐更丰厚的利润，中国的许多低成本制造商都热衷于收购拿球性知名品牌。但一些率先在西方国家购得知名品牌的中国企业却出现了消化不良的现象。