Andrew MacFarlane

A review of ontology based query expansion

This paper examines the meaning of context in relation to ontology based query expansion and contains a review of query expansion approaches. The various query expansion approaches include relevance feedback, corpus dependent knowledge models and corpus independent knowledge models. Case studies detailing query expansion using domain-specific and domain-independent ontologies are also included. The penultimate section attempts to synthesise the information obtained from the review and provide success factors in using an ontology for query expansion. Finally the area of further research in applying context from an ontology to query expansion within a newswire domain is described.

Parallel search using partitioned inverted files

Examines the searching of partitioned inverted files with particular emphasis on issues that arise from different types of partitioning methods. Two types of index partitions are investigated, namely term identifier (TermId) partitioning and document identifier (DocId) partitioning. We describe the search operations implemented in order to support parallelism in probabilistic searching. We also describe higher-level features, such as search topologies, in parallel search methods. The results from runs on the two types of partitioning are compared and contrasted. We conclude that, within our framework, the DocId method is the best.

Field-weighted XML retrieval based on BM25

This is the first year for the Centre for Interactive Systems Research participation of INEX. Based on a newly developed XML indexing and retrieval system on Okapi, we extend Robertson’s field-weighted BM25F for document retrieval to element level retrieval function BM25E. In this paper, we introduce this new function and our experimental method in detail, and then show how we tuned weights for our selected fields by using INEX 2004 topics and assessments. Based on the tuned models we submitted our runs for CO.Thorough, CO.FetchBrowse, the methods we propose show real promise. Existing problems and future work are also discussed.

Teaching and learning in information retrieval

A literature review of pedagogical methods for teaching and learning information retrieval is presented. From the analysis of the literature a taxonomy was built and it is used to structure the paper. Information Retrieval (IR) is presented from different points of view: technical levels, educational goals, teaching and learning methods, assessment and curricula. The review is organized around two levels of abstraction which form a taxonomy that deals with the different aspects of pedagogy as applied to information retrieval. The first level looks at the technical level of delivering information retrieval concepts, and at the educational goals as articulated by the two main subject domains where IR is delivered: computer science (CS) and library and information science (LIS). The second level focuses on pedagogical issues, such as teaching and learning methods, delivery modes (classroom, online or e-learning), use of IR systems for teaching, assessment and feedback, and curricula design. The survey, and its bibliography, provides an overview of the pedagogical research carried out in the field of IR. It also provides a guide for educators on approaches that can be applied to improving the student learning experiences.

Query exhaustivity, relevance feedback and search success in automatic and interactive query expansion

This study explored how the expression of search facets and relevance feedback (RF) by users was related to search success in interactive and automatic query expansion in the course of the search process. Search success was measured both in the number of relevant documents retrieved, whether identified by users or not. Research design consisted of 26 users searching for four TREC topics in Okapi IR system, half of the searchers using interactive and half automatic query expansion based on RF. The search logs were recorded, and the users filled in questionnaires for each topic concerning various features of searching. The results showed that the exhaustivity of the query was the most significant predictor of search success. Interactive expansion led to better search success than automatic expansion if all retrieved relevant items were counted, but there was no difference between the methods if only those items recognised relevant by users were observed. The analysis showed that the difference was facilitated by the liberal relevance criterion used in TREC not favouring highly relevant documents in evaluation.

Meaning, communication, music: towards a revised communication model

Purpose – If an information retrieval system is going to be of value to the user then it must give meaning to the information which matches the meaning given to it by the user. The meaning given to music varies according to who is interpreting it – the author/composer, the performer, cataloguer or the listener – and this affects how music is organized and retrieved. This paper aims to examine the meaning of music, how meaning is communicated and suggests this may affect music retrieval.Design/methodology/approach – Musicology is used to define music and examine its functions leading to a discussion of how music has been organised and described. Various ways of establishing the meaning of music are reviewed, focussing on established musical analysis techniques. It is suggested that traditional methods are of limited use with digitised popular music. A discussion of semiotics and a review of semiotic analysis in western art music leads to a discussion of semiotics of popular music and examines ideas of Midd...

Term context models for information retrieval

At their heart, most if not all information retrieval models utilize some form of term frequency.The notion is that the more often a query term occurs in a document, the more likely it is that document meets an information need. We examine an alternative. We propose a model which assesses the presence of a term in a document not by looking at the actual occurrence of that term, but by a set of non-independent supporting terms, i.e. context. This yields a weighting for terms in documents which is different from and complementary to tf-based methods, and is beneficial for retrieval.

Creative professional users' musical relevance criteria

Although known item searching for music can be dealt with by searching metadata using existing text search techniques, human subjectivity and variability within the music itself make it very difficult to search for unknown items. This paper examines these problems within the context of text retrieval and music information retrieval. The focus is on ascertaining a relationship between music relevance criteria and those relating to relevance judgements in text retrieval. A data-rich collection of relevance judgements by creative professionals searching for unknown musical items to accompany moving images using real world queries is analysed. The participants in our observations are found to take a socio-cognitive approach and use a range of content- and context-based criteria. These criteria correlate strongly with those arising from previous text retrieval studies despite the many differences between music and text in their actual content.

The effect of dyslexia on information retrieval: A pilot study

Purpose – The purpose of this paper is to resolve a gap in the knowledge of how people with dyslexia interact with information retrieval (IR) systems, specifically an understanding of their information‐searching behaviour.Design/methodology/approach – The dyslexia cognitive profile is used to design a logging system, recording the difference between two sets of participants: dyslexic and control users. A standard Okapi interface is used – together with two standard TREC topics – in order to record the information searching behaviour of these users.Findings – Using the log data, the differences in information‐searching behaviour of control and dyslexic users, i.e. in the way the two groups interact with Okapi, are established and it also established that qualitative information collected (such as experience etc.) may not be able to account for these differences. Evidence from query variables was unable to distinguish between groups, but differences on topic for the same variables were recorded. Users who v...

Evaluation of web search for the information practitioner

Purpose – The aim of the paper is to put forward a structured mechanism for web search evaluation. The paper seeks to point to useful scientific research and show how information practitioners can use these methods in evaluation of search on the web for their users.Design/methodology/approach – The paper puts forward an approach which utilizes traditional laboratory‐based evaluation measures such as average precision/precision at N documents, augmented with diagnostic measures such as link broken, etc., which are used to show why precision measures are depressed as well as the quality of the search engines crawling mechanism.Findings – The paper shows how to use diagnostic measures in conjunction with precision in order to evaluate web search.Practical implications – The methodology presented in this paper will be useful to any information professional who regularly uses web search as part of their information seeking and needs to evaluate web search services.Originality/value – The paper argues that the ...