An analysis on document length retrieval trends in language modeling smoothing

Document length is widely recognized as an important factor for adjusting retrieval systems. Many models tend to favor the retrieval of either short or long documents and, thus, a length-based correction needs to be applied for avoiding any length bias. In Language Modeling for Information Retrieval, smoothing methods are applied to move probability mass from document terms to unseen words, which is often dependant upon document length. In this article, we perform an in-depth study of this behavior, characterized by the document length retrieval trends, of three popular smoothing methods across a number of factors, and its impact on the length of documents retrieved and retrieval performance. First, we theoretically analyze the Jelinek–Mercer, Dirichlet prior and two-stage smoothing strategies and, then, conduct an empirical analysis. In our analysis we show how Dirichlet prior smoothing caters for document length more appropriately than Jelinek–Mercer smoothing which leads to its superior retrieval performance. In a follow up analysis, we posit that length-based priors can be used to offset any bias in the length retrieval trends stemming from the retrieval formula derived by the smoothing technique. We show that the performance of Jelinek–Mercer smoothing can be significantly improved by using such a prior, which provides a natural and simple alternative to decouple the query and document modeling roles of smoothing. With the analysis of retrieval behavior conducted in this article, it is possible to understand why the Dirichlet Prior smoothing performs better than the Jelinek–Mercer, and why the performance of the Jelinek–Mercer method is improved by including a length-based prior.

A role for message TV in education

Conclusion The role of message TV in education will change with advancing technology and improving instructional design. As a stand alone activity, message TV may be too subjective an experience with too short a duration to expect enduring attitude and value changes. More research into the use of the medium as a stand alone activity is required. However, since message TV is a more effective medium for impressing with images than transmitting abstract data, it can play the affective instructional role as the strategic component within a program that uses a variety of activities to facilitate attitude and value cultivation. Message TV is a very powerful tool for persuasion that illustrates, dramatizes, and makes concrete the program’s objectives. Both of these productions operate on budgetary demands typical of educational institutions: resourcefulness, innovation, and dollar s-t-r-e-t-c-h-i-n-g. Our computer graphics are created on an Omega 500 with extra memory and a genlock device. For special effects we use a Chinon CV-T70 VHS Camcorder camera with special digital effects. This equipment belongs to our talented videographics creator, Rex Suba, who teaches high school media production. He gave a showcase presentation at AECT’s 1988 convention entitled “Desk Top Video: Low Cost Choice For Instruction” and demonstrates the innovative educational applications of his affordable equipment.     

Web Design Trends in Academic Libraries—A Longitudinal Study

This study examines several key design elements of 37 academic library Web sites (members of the Association of Southeastern Research Libraries) and how they have changed between 2012 and 2015. While several studies have reviewed library Web sites looking for common design elements and content, the present work may be the first to look at the design elements of a large group of library Web sites over time. This study has two main goals: to present an objective analysis of the navigation and search interface designs at research university library Web sites, and to assess the usage of Web-scale discovery systems and content management systems in libraries. Other areas explored include when sites were most recently redesigned and whether sites have adopted a mobile-friendly, responsive design. Notable findings include a very high usage of Web-scale discovery systems, an increasing adoption of open source content management systems, and increasing implementation of responsive design. Also noted was a strong and growing standardization in navigation design. This study concludes with a review of the trends and discussion of current design patterns in academic library Web sites.     

East African higher education from the community standpoint

The concept of community education is considered in relation to higher education in East Africa. The case of the University of Dar es Salaam is taken as an example to show how the concept has been adapted to meet the needs of a university in a developing society. Orientations towards the community in terms of teaching, research and other activities are described. Problems of access, admission, control and participation are considered in the context of the changed conditions within which the university must operate. The suggestion is made that experience shows that an institution can re-order itself in such a way as to contribute more effectively to the national community it serves.An earlier version of this article was prepared for a Seminar on Education and the Community in Africa held at the Centre of African Studies, University of Edinburgh 18–20 June 1976.     

Sharing centers: An alternative approach to show and tell

Show and tell is a common activity in many early childhood settings yet many teachers question its value. The purpose of this article is to review the benefits and limitations of the traditional approaches to show and tell and to present an alternative approach based upon appropriate practices that was implemented in a multi-age classroom of 3- to 5-year-old children.