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Lecture 13 • Housekeeping • Term Projects • Evaluations • Morse, E., Lewis, M., and Olsen, K. (2002) Testing Visual Information Retrieval Methodologies Case Study: Comparative Analysis of Textual, Icon Graphical and 'Spring' DisplaysJournal of the American Society for Information Scienceand Technology (JASIST) PDF • Reiterer H., Mußler G., Mann T.: Visual Information Retrieval for the WWW, in: Smith M.J. et al. (eds.), Usability Evaluation and Interface Design, Lawrence Erlbaum, 2001 PDF • searchCrystal Studies
Prototype Project • Motivate domain choice. • Perform task and need analysis. • Describe design approach and information visualization principles used. • Develop prototype. • Have an "domain expert" use the prototype and provide feedback. • Class PresentationYou have 15 min. to describe task analysis and your design approach.Demonstrate your prototype.Report on the "domain expert" feedback. • Create Report20 to 25 pages, written as a standard paper 10pt, double-spacedProvide screenshots of prototype and explain design approach.Include URL of prototype. • Hand-inHardcopy of report.Post report online and send instructor an email with the URL.
Text Retrieval Visualizations – Evaluations : Morse et al. • Many Tools Proposed • Few Tested and Often Inconclusive / Fare Poorly • Simplify Evaluation Focus on Method (instead of implementation) Only Static Aspects • POI = Point of Interest Visualizations • Position Coding • Glyph = Graphical Entity • Conveys data values via attributes such as shape, size, color
searchCrystal – Studies • Validate Design Approach • How does Overlap between Results Actually Correlate with Relevance? • User Study
Overlap between Search Results Correlated with Relevance? • Method • Use Ad-hoc track data for TREC 3, 6, 7, 8 • Systems search the SAME Database • Automatic Short Runs • 50 Topics and 1,000 Documents per topic 50,000 documents • Retrieval systems can submit multiple runs Select Best Run based Mean Average Precision TREC 319systems928,709documents found TREC 624systems1,192,557documents found TREC 728systems1,327,166documents found TREC 835systems1,723,929documents found • Compute Average by summing over all 50 topics and divide by 50
How does Overlap Correlate with Relevance? Percentage of Documents that are Relevant Systems Authority Effect
TREC 8 – Impact of Average Rank Position? • Compute overlap structure between top 50 search results of 35 random groupings of 5 retrieval systems for 50 topics. Percentage of Documents that are Relevant Systems Ranking Effect
searchCrystal – Studies • How does Overlap between Search Results Correlate with Relevance? • Authority Effect– the more systems that find a document, the greater the probability that it is relevant • Ranking Effect– the higher up a document in a ranked list and the more systems that find it, the greater the probability of its relevance • Validates searchCrystal’s Design Approach • searchCrystal Visualizes Authority & Ranking Effects • searchCrystal can Guide User’s Exploration Toward Relevant Documents
searchCrystal – Studies • Validate Design Approach • How does Overlap between Results Actually Correlate with Relevance? • User Study • http://www.scils.rutgers.edu/~aspoerri/study/UserStudy.swf
User Study – Compare Cluster Bull’s Eye and RankSpiral • Nine undergraduates. • Short Introduction and No Training. • Randomized presentation order of data sets and display type. • Subject selects ten document; • Visual feedback about correct top 10 • http://www.scils.rutgers.edu/~aspoerri/study/UserStudy.swf • Test for Cluster Bull’s Eye and RankSpiral displays: • 1) How well can novices use visual cues to find the documents that are most likely to be relevant? • 2) Performance difference in terms of effectiveness and/or efficiency? • 3) How much document’s distance from the display center will interfere with the size coding used to encode its probability of being relevant
User Study – Results • Hypothesis 1: “Novices can perform the task.” • Error is minimal for the top 7 documents and increases rapidly after the top 7 documents for both displays. • Novice users can use the Cluster Bulls-Eye and RankSpiral displays to select highly relevant documents, especially the top 7 documents. • Hypothesis 2: “RankSpiral outperforms Cluster Bulls-Eye.” • 8 of the 9 subjects performed the task faster using the RankSpiral. • Average time difference was 7.89 seconds. • The one-sided T-test value is 0.033, which is significant at the 0.05 level. • 7 out of 9 subjects performed the task more effectively using the RankSpiral. • Average “relevance score” difference is 0.034. • The one-sided T-test value is 0.037, which is significant at the 0.05 level. • Hypothesis 3: “Distance from center dominant cue.”
Discussion • Relax searchCrystal’s design principles? • Mapping documents found by the same number of engines into the same concentric ring. • Option: Distance and Size encode likelihood that a document is relevant. • Internet search results: • Concentric rings are of value, because it is much harder to estimate a document’s probability of being relevant.
searchCrystal - Studies • Authority & Ranking Effects Comparing Results of All Retrieval Systems at once Comparing Results of Random Subsets of Five Systems Validating searchCrystal’s Design Principles • User Study Identify Top 10 Docs in Cluster Bull’s Eye and RankSpiral • Novice Users can use the two searchCrystal displays • Statistical Difference between two displays • Distance from center is dominant visual feature
What is Popular on Wikipedia?Why? • Please read the two papers published by me in First Monday:http://www.firstmonday.org/ISSUES/issue12_4/ • Approach • 1 Visualize Popular Wikipedia Pages • Overlap between 100 Most Visited Pages on Wikipedia for September 2006 to January 2007 • Information Visualization helps to gain quick insights • 2 Categorize Popular Wikipedia Pages • 3 Examine Popular Search Queries • 4 Determine Search Result Position of Popular Wikipedia pages • 5 Implications