No abstract

No abstract

We discuss whether it is feasible to build intelligent ruleor weight-based algorithms into general-purpose software for interactive thesaurus navigation. We survey some approaches to the problem reported in the literature, particularly those involving the assignment of "link weights" in a thesaurus network, and point out some problems of both principle and practice. We then describe investigations which entailed logging the behavior of thesaurus users and testing the effect of thesaurus-based query enhancement in an IR system using term weighting, in an attempt to identify successful strategies to incorporate into automatic procedures. The results cause us to question many of the assumptions made by previous researchers in this area.

The growth of UK public interest in health in the last decade is reflected by the inclusion in most national newspapers of regular health or medical sections. These potentially allow subjects to be covered in detail, with more background information and useful advice. This paper reports on a content analysis study of eight national newspapers, which aimed to obtain an overview of press health coverage, to compare the coverage of popular and quality papers, and to analyse differences in health topic coverage between 1981 and 1990. The subject coverage, information provision and presentation of health related articles were considered. The most common subject categories were diseases, preventive medicine (including diet and exercise) and the National Health Service. Class inequalities in health received very little coverage. Clear differences were confirmed between quality broadsheet and popular tabloid newspapers. Quality papers provided more scientific information about health and paid more attention to political contexts. They made more use of authoritative journals and reports than popular papers, which focused on individual case histories and tended to quote a lay viewpoint. Popular press articles were generally more sensationalized and less objective in their reporting style. Newspapers do not exist solely to further public understanding, but have potential to contribute to it. Some informative, useful articles about health are found, but the study shows room for improvement, especially among the papers whose readership is concentrated in lower socio-economic groups.

The second half of a ‘before and after’ study to evaluate the impact of an online catalogue on subject searching behaviour is reported. A holistic approach is adopted encompassing both catalogue use and browsing at the shelves for catalogue users and non‐users. Verbal and non‐verbal data were elicited from searchers using a combined methodology including talk‐aloud technique, observation and a screen logging facility. An extensive qualitative analysis was carried out correlating expressed topics, search formulation strategies and documents retrieved at the shelves. The online catalogue environment does not appear to have increased the extent of subject searching nor the use of the bibliographic tool. The manual precis index supported a contextual approach for broad and more interactive search formulations whereas the opac encouraged a matching approach and narrow formulations with fewer but user generated formulations. The success rate of the online catalogue was slightly better than that of the manual tools but fewer items were retrieved at the shelves. Non‐users of the bibliographic tools seemed to be just as successful. To improve retrieval effectiveness it is suggested that online catalogues should cater for both matching and contextual approaches to searching. Recent research indicates that a more interactive process could be promoted by providing query expansion through a combination of searching aids for matching, for search formulation assistance and for structured contextual retrieval.