PhD Defense Klaar Vanopstal

Posted on Aug. 28, 2013

Klaar Vanopstal successfully defended her PhD on August 27th, 2013. Her dissertation entitled Impact of language skills and system experience on medical information retrieval was supervised by Prof. dr. Godelieve Laureys (Ghent University), Prof. dr. Joost Buysschaert (University College Ghent/Ghent University) and Prof. dr. Robert Vander Stichele (Ghent University). Her research presents an interdisciplinary study in medical information retrieval. In the first theoretical part the focus is on vocabularies for medical information retrieval which quickly reveals that many terms used in this field are polysemous and sometimes even incorrect. In her thesis she provides a solution to this problem by listing a definition for each of the terms and for each of the fields in which they are used: linguistics, knowledge management and/or bibliographical retrieval. In the second part of her study she analyzes the various difficulties nursing students experience when they search for medical information. A retrieval experiment in which she assembled data of Dutch-speaking and English-speaking bachelor's and master's nursing students enabled her to perform three analyses. In a first analysis she found that especially the English language skills in Dutch-speaking searchers had an impact and that the more experienced searchers were better at selecting the appropriate MeSH terms and at distinguishing relevant citations from irrelevant ones. A second analysis revealed that the mean difference in search behaviours between best and worst performers lies in the correction of errors. In a final contrastive analysis she uncovered that although the query formulation process was more fluent in the native speakers they did not achieve better results or higher information gain. On the contrary: the Dutch-speaking, more experienced students achieved higher weighted recall, and her analysis showed that they were better at relevance judgment. The main conclusion of her dissertation is that language skills have an impact on the fluency of the search process, but the overall success of the search depends on other factors as well, such as searching skills and general research skills.