The value of structured abstracts in information retrieval from MEDLINE

Objective: To determine whether information retrieval might be enhanced by making each component of a structured abstract a separately searchable field. Design: Parallel searches on records arranged so that each abstract could either be searched in its entirety or as a collection of structured fields. Subjects: Records about cardiovascular disease downloaded from MEDLINE and tested against clinical questions derived from a concurrent survey of CD-ROM use in three health science libraries. Intervention: The investigators identified terms used to structure abstracts on MEDLINE and imported the abstracts into an Idealist database prior to searching using keywords from clinical questions. Measurements and main results: recall and precision rates are given for each question in the ‘structured’ and the ‘unstructured’ set of records. Conclusions: Use of structured, rather than unstructured, abstracts improves precision at the ex-pense of recall and places heavier demands upon the searcher’s skill in choosing the correct fields within the abstract to search. Further investigation requires more accurate simulation of MEDLINE software that utilizes features such as MeSH terms, explode, facilities and delimiters.     

Improving GIS Consultations： A Case Study at Yale University Library

面向服务的体系结构、对等网络和网格技术的发展为数宇图书馆体系结构的研究和应用带来了新的机遇，使其在开放性和柔性方面的拓展成为可能。下一代数字图书馆应当是能为更多用户服务的、自适性更强的服务组织，它是以联邦模式进行资源库的构建和服务的组织。与传统数字图书馆相比，下一代数字图书馆的体系结构将更为分布和动态，从而适应资源库、元数据和服务所呈现出的高度异构性。     

Disentangling Race: Re-Narrating Apartheid Sport?

Abstract

This paper involves a search for interracial entanglements in South African sport and considers how these experiences may be narrated. The paper comprises three sections. The first provides an overview of traditional narratives of apartheid and apartheid sport that focus on race as a perpetual marker of social division. The second section shifts attention to the gaps, blind spots, mistakes, paradoxes, ironies, anomalies, ambiguities and invisibilities in the structures of apartheid that allowed for racial encounters and entanglements. The paper concludes with a discussion about the methodological and political implications of incorporating racial entanglements into narratives of apartheid sport.     

The questionable role of higher education as an occupational screening device

Employers optimally pursue activities which facilitate the coordinating of employee characteristics and the requirements of the job. One allegedly important employee characteristic is the level of education. Employees with higher levels of education are rewarded with higher wages than employees with lower levels. This may occur if higher levels of education make an employee truly more productive or if because of an employer's beliefs only those individuals with higher levels of education are allowed to enter the higher paying positions (occupational screening).The above propositions are testable, depending crucially upon the theoretical model employed for determining occupational choices. We shall compare the implications of two possible occupation choice models: (1) enter the job which offers the highest lifetime income, (2) enter the job which offers the highest level of overall satisfaction. We estimate these two models using the NBER-TH data sample. By distributing our estimated results and the actual distribution of occupations over the education levels of high school, some college and BA we can see if more or less people are expected to enter specific occupations at each education level. Support for screening exists if more people are expected in high status occupations at low education levels than are actually in those occupations.When comparing the estimated results for each model we see different outcomes emerge. The latter indicates that screening does not exist while the former does. We present arguments as to why we feel that the second model is the more correct and appropriate and, consequently, why we feel that education is not an effective screening device.     

The necessity of each phase of the learning cycle in teaching high school physics

The learning cycle is a method of teaching—it is also a curriculum organization principle and is derived directly from the mental functioning model invented by Piaget. Although Jean Piaget contributed to the formation of the learning cycle (Piaget, 1973), its present structure has to be attributed to Dr. Robert Karplus and the persons who developed the materials of the Science Curriculum Improvement Study (SCIS). It was through the SCIS activities that many of us learned how to develop curricula and teach with the learning cycle. The learning cycle is built upon the premise that three distinct phases are necessary in developing understanding of a concept, that those phases have a definite sequence, and each phase has a definite structure or form. The research done in testing the form variable has already been reported in this journal (Renner, Abraham, & Birnie, 1985). This report explores whether or not each learning-cycle phase is necessary in learning a concept.     

A SYSTEMIC,STUDENT-CENTERED STUDY OF UNIVERSITY SERVICE

This paper discusses the methods and findings ofthe Student Focus Project, a sixmonth study of studentperceptions of service at a large university inBrisbane, Australia. The study paneled 24 focus groups of undergraduate students to assess theirbeliefs about a pretested set of questions concerningpositive and negative aspects of university life,successes and frustrations with university service,attempts to overcome the obstacles of university life,and what students expect from their relationship to theuniversity. Of the themes identified in the StudentFocus study, it was found that malignantbureaucracy and the balkanization ofInformation are systemic factors that negativelyinfluence student perceptions of the quality ofuniversity service. It was also found that studentstrategies for service recovery can contribute to the overall confusion andpoor performance of university services.     

Mathematical Flexibility: Aspects of a Continuum and the Role of Prior Knowledge

Abstract

Psychologists and mathematics educators have long viewed flexibility as critical to students’ mathematical development. In this paper, we focused on the multidimensional nature of flexibility to better understand how preference, knowledge, and use of effective methods for solving algebra problems are related. In Study 1, we identified research-based aspects of flexibility with algebra and assessed students on them following a two-step equations unit. Results indicated that certain aspects of flexibility develop prior to others and that prior knowledge of algebra plays a significant role in that development. Study 2 confirmed and elaborated on these results using a larger sample size. Implications for theory and for supporting flexibility in classrooms are discussed.