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Improving the quality of responses to health search queries by evidence-based context. Peter Bailey Project Leader, Search and Delivery, ICT Centre 10 August 2007. Health searching – what will benefit me most?. Accuracy – relevance Accountability – quality Anonymity – privacy
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Improving the quality of responses to health search queries by evidence-based context Peter Bailey Project Leader, Search and Delivery, ICT Centre 10 August 2007
Health searching – what will benefit me most? • Accuracy – relevance • Accountability – quality • Anonymity – privacy • Current “generic” web search faces many challenges CSIRO Improving the quality of responses to health search queries by evidence-based context
Accuracy – relevance • Respond to possible information needs with • Highly relevant information • Assistance in refining need • Meet this goal more successfully by better use of contextual information about the person • Their task requirements, e.g. • Research • Self diagnosis • Checking medical recommendations • Their personal circumstances, e.g. • Location, age, sex, … • Availability of treatments • Current health status CSIRO Improving the quality of responses to health search queries by evidence-based context
Health search – depression CSIRO Improving the quality of responses to health search queries by evidence-based context
Health search – obesity CSIRO Improving the quality of responses to health search queries by evidence-based context
Health search – diet CSIRO Improving the quality of responses to health search queries by evidence-based context
Health search – fat CSIRO Improving the quality of responses to health search queries by evidence-based context
Accountability – quality • Low-quality Web information • Lots of it • Serious consequences if misleading advice followed • How to get rid of it from results? • Evidence-based medicine information • Treatments recommended according to strength of scientific evidence • Multiple randomised controlled trials • How to maximise it in results? CSIRO Improving the quality of responses to health search queries by evidence-based context
Health search – depression treatments CSIRO Improving the quality of responses to health search queries by evidence-based context
Automated quality assessment (AQA) • Relevance and quality queries were learned • An extension and application of relevance feedback techniques • Selection of indicative query terms using Term Selection Values (TSVs) • Single word terms and two-word phrases; highest 20 TSVs selected (for relevance) and 29 words and 20 phrases (for quality) • Numerical weights assigned using Robertson-Spärk Jones formula • Training documents used with background pool of non-relevant, or relevant but not high quality documents • Combination of relevance and quality scores for websites • Scoring algorithms normalised, and then scaled to be comparable with human rating scales CSIRO Improving the quality of responses to health search queries by evidence-based context
AQA – correlations • AQA site scores were correlated 0.85 (p < .001) with human expert judgements of site quality • Linear correlation, with additional hierarchical multiple regression analysis • Compares almost with inter-rater reliability • Small and non-significant correlation of PageRank with expert judgements (r=0.23, p=.22) • PageRank calculated from Google Toolbar’s value (0-10) • Excluding PageRank site scores of 0, a correlation exists of 0.61 (p<.002) • Still significantly lower than the association between AQA and evidence-based quality scores • Site score then used as the AQA metric for result filtering, re-ranking, or crawler selection policy CSIRO Improving the quality of responses to health search queries by evidence-based context
AQA – in action CSIRO Improving the quality of responses to health search queries by evidence-based context
AQA – performance and analysis • Measurements are on a site basis, not a page basis • Judging took 6 months • AQA-based search engines outperformed others • Rank-averaging outperformed on quality • Filtering outperformed on relevance • Quality focused crawling is more viable than manual definition CSIRO Improving the quality of responses to health search queries by evidence-based context
AQA – for quality focused crawls • Poor quality pages found early in crawl • Continued growth in high quality pages as crawl progresses • Relies on unbroken link chains between seedlist and relevant high quality content • Generic search engines with high crawl coverage have an advantage • Opportunity however for dedicated vertical search CSIRO Improving the quality of responses to health search queries by evidence-based context
Anonymity – privacy • How do I preserve my privacy when interacting with a search engine? • Health search matters are some of the most deeply personal • No wish to hand this out to anyone • See AOL query logs release (Aug 2006), and recent announced changes by Google, AOL, … on information retention • Imagine if spam email started drawing on your searches • Also advertisements are not always correlated with quality health advice • Spam and other adversarial techniques need combating CSIRO Improving the quality of responses to health search queries by evidence-based context
Future work • Australia (and other countries) faces a growing health challenge of obesity • Associated with poor health in later life, such as type 2 diabetes, increased heart disease, liver disorder, … • Currently applying AQA methods to health topic of obesity • Expert classification of obesity information from web sites by CMHR • Need to learn relevance and quality queries • Conduct comparative experiments • Can AQA apply generically? • How to obtain health topic specific training material for learning AQA CSIRO Improving the quality of responses to health search queries by evidence-based context
Acknowledgements • Pictures licensed under Creative Commons from Flickr • Chinese hospital - http://www.flickr.com/photos/shapeshift/ • Baby footprint - http://www.flickr.com/photos/hamed/ • Three girls - http://www.flickr.com/photos/malingering/ • Darts - http://www.flickr.com/photos/ramk13/ • Scrolls - http://www.flickr.com/people/felix42/ • Laptop browser - http://www.flickr.com/photos/shapeshift/ • Lego heads - http://www.flickr.com/photos/richard_am/ • Work being carried out in collaboration with: • Kathy Griffiths (ANU), David Hawking (CSIRO), Ramesh Sankaranarayana (ANU), Thanh Tang (ANU) • Funding by: • CSIRO ICT Centre • Australian National University • Microsoft Research Asia CSIRO Improving the quality of responses to health search queries by evidence-based context
ICT Centre, Search and Delivery Peter Bailey Project leader Phone: +61 2 6216 7055 Email: Peter.Bailey@csiro.au Web: www.csiro.au/ict Thank you Contact UsPhone: 1300 363 400 or +61 3 9545 2176Email: Enquiries@csiro.au Web: www.csiro.au