1,721,040 research outputs found
Semantic search as inference : applications in health informatics
No full textThis thesis developed new search engine models that elicit the meaning behind the words found in documents and queries, rather than simply matching keywords. These new models were applied to searching medical records: an area where search is particularly challenging yet can have significant benefits to our society
Why Assessing Relevance in Medical IR is Demanding
No full textThis study investigates if and why assessing relevance of clinical records for a clinical retrieval task is cognitively de-manding. Previous research has highlighted the challenges and issues information retrieval systems are faced with when determining the relevance of documents in this domain, e.g., the vocabulary mismatch problem. Determining if this as-sessment imposes cognitive load on human assessors, and why this is the case, may shed lights on what are the (cogni-tive) processes that assessors use for determining document relevance (in this domain). High cognitive load may impair the ability of the user to make accurate relevance judgements and hence the design of IR mechanisms may need to take this into account in order to reduce the load
Integrating Understandability in the Evaluation of Consumer Health Search Engines
No full textIn this paper we propose a method that integrates the no-tion of understandability, as a factor of document relevance, into the evaluation of information retrieval systems for con-sumer health search. We consider the gain-discount eval-uation framework (RBP, nDCG, ERR) and propose two understandability-based variants (uRBP) of rank biased pre-cision, characterised by an estimation of understandability based on document readability and by different models of how readability influences user understanding of document content. The proposed uRBP measures are empirically con-trasted to RBP by comparing system rankings obtained with each measure. The findings suggest that considering under-standability along with topicality in the evaluation of in-formation retrieval systems lead to different claims about systems effectiveness than considering topicality alone
Generating clinical queries from patient narratives
No full textThis paper investigates how automated query generation methods can be used to derive effective ad-hoc queries from verbose patient narratives. In a clinical setting, automatic query generation provides a means of retrieving information relevant to a clinician, based on a patient record, but without the need for the clinician to manually author a query. Given verbose patient narratives, we evaluated a number of query reduction methods, both generic and domain specific. Comparison was made against human generated queries, both in terms of retrieval effectiveness and characteristics of human queries. Query reduction was an effective means of generating ad-hoc queries from narratives. However, human generated queries were still significantly more effective than automatically generated queries. Further improvements were possible if parameters of the query reduction methods were set on a per-query basis and a means of predicting this was developed. Under ideal conditions, automated methods can exceed humans. Effective human queries were found to contain many novel keywords not found in the narrative. Automated reduction methods may be handicapped in that they only use terms from narrative. Future work, there- fore, may be directed toward better understanding effective human queries and automated query rewriting methods that attempt to model the inference of novel terms by exploiting semantic inference processes
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
What makes an effective clinical query and querier?
No full textIn this paper, we perform an in-depth study into how clinicians represent their information needs and the influence this has on information retrieval (IR) effectiveness. While much research in IR has considered the effectiveness of IR systems, there is still a significant gap in the understanding of how users contribute to the effectiveness of these systems. The paper aims to contribute to this by studying how clinicians search for information.\ud
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Multiple representations of a information need — from verbose patient case descriptions to ad-hoc queries — were considered in order to understand their effect on retrieval. Four clinicians provided queries and performed relevance assessment to form a test collection used in this study. The different query formulation strategies of each clinician, and their effectiveness, were investigated.\ud
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The results show that query formulation had more impact on retrieval effectiveness than the particular retrieval systems used. The most effective queries were short, ad-hoc keyword queries. Different clinicians were observed to consistently adopt specific query formulation strategies. The most effective queriers were those who, given their information need, inferred novel keywords most likely to appear in relevant documents.\ud
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This study reveals aspects of how people search within the clinical domain. This can help inform the development of new models and methods that specifically focus on the query formulation process to improve retrieval effectiveness
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