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This paper discusses the SWISH system that automatically categorizes search results by utilizing hierarchical category structures. It explains the text classification models, user interface design, and user studies conducted to evaluate the system's effectiveness in organizing information online.
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Bringing Order to the Web: Automatically Categorizing Search Results Hao Chen, CS Division, UC Berkeley Susan Dumais, Microsoft Research ACM:CHI April 4, 2000
List Organization Category Org (SWISH) Organizing Search Results Query: jaguar
Outline • Background • Using category structure to organize information • SWISH SystemSearching With Information Structured Hierarchically • Text classification • User interface • User Study • Future Work
Using Category Structure • To Organize Information • Superbook, Cat-a-Cone, etc. • To Help Web Search • Yahoo!, Northern Light • What’s New in SWISH? • Automatic categorization of new documents • User interface that tightly couples hierarchical category structure with search results • User study for the new user interface
SWISH System • Combines the Advantages of • Manually crafted & easily understood directory structure • Broad coverage from search engines • System Components • Text classification models • User interface
Text Classification • Text Classification • Assign documents to one or more of a predefined set of categories • E.g., News feeds, Email - spam/no-spam, Web data • Manually vs. automatically • Inductive Learning for Classification • Training set: Manually classified a set of documents • Learning: Learn classification models • Classification: Use the model to automatically classify new documents
Automotive • Business & Finance • Computers & Internet • Entertainment & Media • Health & Fitness • Hobbies & Interests • Home & Family • People & Chat • Reference & Education • Shopping & Services • Society & Politics • Sports & Recreation • Travel & Vacations Training Set:LookSmart Web Directory • Category Structure (spring 99) • 13 top-level categories • 150 second-level categories • Training Set • ~50k web pages; chosen randomly from all cats • Top-level Categories
Learning & Classification • Support Vector Machine (SVM) • Accurate and efficient for text classification (Dumais et al., Joachims) • Model = weighted vector of words • “Automobile” = motorcycle, vehicle, parts, automobile, harley, car, auto, honda, porsche … • “Computers & Internet” = rfc, software, provider, windows, user, users, pc, hosting, os, downloads ... • Hierarchical Models • 1 model for N top level categories • N models for second level categories • Very useful in conjunction w/ user interaction
... web search results local search results Train (offline) Classify (online) manually classified web pages SVM model SWISH Architecture
Interface Characteristics • Problems • Large amount of information to display • Search results • Category structure • Limited screen real estate • Solutions • Information overlay • Distilled information display
Information Overlay • Use tooltips to show • Summaries of web pages • Category hierarchy
Category Interface List Interface User Study - Conditions
User Study • Participants: • 18 intermediate Web users • Tasks • 30 search taskse.g., “Find home page for Seattle Art Museum” • Search terms are fixed for each task • Experimental Design • Category/List – within subjects • 15 search tasks with each interface • Order (Category/List First) – counterbalanced between subjects • Both Subjective and Objective Measures
Subjective Results • 7-point rating scale (1=disagree; 7=agree) • Questions:
Use of Interface Features Average Number of Uses of Feature per Task
Search Time Category: 56 secs List: 85 secs p < .002 50% faster with Category interface
Search Time by Query Difficulty • Top20: 57 secs • NotTop20: 98 secs • No reliable interaction between query difficulty and interface condition • Category interface is helpful for both easy and difficult queries
Summary • Text Classification • Organize search results • Use hierarchical category models • Classify new web pages on-the-fly • User Interface • Tightly couple search results with category structure • Allow manipulation of presentation of category structure • User Study • Suggest strong preference and performance advantages for categorically organized presentation of searchresults
Open Issues • Improve Accuracy of Classification Algorithms • Enhance User Interface • Heuristics for selecting categories and pages to display • Query_Match: rank of page, and sometimes match score • Categ_Match: p(category for each page) • Integration with non-content information • Conduct End-to-end User Study • More info: • http://research.microsoft.com/~sdumais