The effect of postings information on searching behaviour

Abstract

How postings information is used for inverted file searching was investigated by comparing searches, made by postgraduate students at the Department of Information Studies, of the LISA (Library and Information Science Abstracts) database on CD-ROM with and without postings information.Performance (the number of relevant references, precision and recall) was not significantly different but searches with postings information took more time, and more sets were viewed, than in searches without postings. Postings information was used to make decisions to narrow or broaden the search; to view or print the references. The same techniques were used to amend searches whether or not postings information was available.Users decided that a search was satisfactory on the basis of the search results, and consequently many searches done without postings were still considered satisfactory. However, searchers thought that the lack of postings information had affected 90% of their searches.Differences in search performance and searching behaviour were found in participants who were shown to have different learning styles using the Witkin's Embedded Figures Test and the Lancaster Short Inventory of Approaches to Learning Test. These differences were, in part, explained by the differences in behaviour indicated by their learning styles. 1. Aim and objectives of the study This project [1] investigated the effects of postings information on searching behaviour. By 'postings Correspondence to: Miss F.E. Wood, Department of Information Studies, University of Sheffield, Regent Court, 211 Portobello, Sheffield Sl 4DP, UK. Tel: 0742 768555. Fax: 0742 780300information' we mean the display on the screen of the number of references in a set.Specific objectives were:[1] to identify performance levels for searches with and without postings information using the standard criteria of relevance, recall and precision;(2) to determine to what extent, for what reasons, and in which ways postings information is used in searching; (3) to establish how users behave when postings information is not available; (4) to assess levels of user satisfaction with searches with, and without, postings information; (5) to obtain the views of users on searching with postings information withheld. In addition, it was decided to test the learning styles of participants to ensure that the population was suitably varied in this respect, and to investigate any correlation between cognitive style and searching behaviour. As Logan [2] suggests:Since novice searchers have little online training or experience, they may rely more on basic learning styles to guide their behaviour when online.2. Background to the study The current generation of text retrieval systems is based on the inverted file structure, where postings lists provide rapid access to those documents that contain the terms that have been specified in a user's query. In addition, the postings information provides an important feedback mechanism: for example, additional 'AND' operators can be included in a query...