Interfaces for Selecting and Understanding CollectionsSelecting from CollectionsDoes it Matter?Interfaces over Multiple CollectionsLists of CollectionsExampleSlide 7ExamplesOverviews of CollectionsCategory-based OverviewsMeSH BrowserHiBrowse BrowserConeTreesRadial ViewsHyperbolic ViewsMediaMetroAutomatically Derived OverviewsScatter GatherEvaluation of Scatter-GatherThemescapesMore ThemescapesKohonen MapsEvaluation of Graphical OverviewsExamples, Dialogs, WizardsAutomated Source SelectionInterfaces for Selecting and Understanding CollectionsSelecting from CollectionsCollections are sets of documents that have been coalesced by a human or system.Traditional collections:–NLM’s MedLine–ACM Digital Library–LEXIS-NEXIS–Library/museum resources from a particular donorHow do people with information needs locate and identify the appropriate collections?Does it Matter?Web search engines (e.g. Google) get us the information we need …–well maybeWeb search drops users into the middle of a collection without any understanding of the collection and its overall characteristics.Web search misses–Lots of more structured materials•“the hidden web”–Subscription-based content•Which is likely the best edited, most accurate, and most valuable in specialized domainsInterfaces over Multiple CollectionsInterfaces for Selecting and Understanding Collections–Lists–Overviews–Examples–Automated source selectionLists of CollectionsUsually just provides a list of collection names.–Difficult to select from if user does not know the collections beforehand–Over time people bookmark collections of valueNeed tools for helping users who are outside of their areas of expertiseExampleExampleExamplesOverviews of CollectionsOverviews provide a sense of what is in a collectionOverviews can be–Based on a category or directory structure–Automatically derived from the collectionPresentation of an overview is often a form of information visualizationCategory-based OverviewsMedLine – biomedical collection–Medical Subject Headings (MeSH) consists of 18,000 categories in a directed acyclic graphACM Digital Library – computer science collection–Hierarchy of 1200 catgory (keyword) labelsYahoo – the Web–Graph of directories (probably a DAG)Humans have to place documents in categories–Author for ACM DL, subject experts for MedLine, surfers for YahooMeSH BrowserHiBrowse BrowserConeTreesRadial ViewsHyperbolic ViewsMediaMetroAutomatically Derived OverviewsApply clustering algorithms to document collection–Remember Automatic Global Analysis•Use of co-occurrance and co-citation•Use of distance-based clustering approaches like hierarchic agglomerative clusteringNeed methods to determine labels for clusters–Could be a document•identification of centroid (document most similar to all others)•Identification of hubs (document most mentioned by cluster)–Could be one or more terms•Use most common / best differentiator (using TF-IDF)No human intervention required –but people are likely to be valuable as editorsScatter GatherEvaluation of Scatter-GatherScatter-Gather–Scatter-Gather conveyed overview of collection contents–Scatter-Gather without search was less effective than a basic search–Need to combine clustering with searchThemescapesMore ThemescapesKohonen MapsEvaluation of Graphical OverviewsOne study found that non-experts found the clustering results difficult to use (worse than text-based views like Scatter-Gather)Comparison of Kohonen map and Yahoo–11 of 15 subjects found “interesting” page using Kohonen•8 were able to find same page using Yahoo–14 of 16 subjects found “interesting” page using Yahoo•2 were able to find same page using Kohonen–Subjects liked ability to jump between categories without backing out of current categoryUnsupervised thematic overviews probably better for giving a gist of what is in a collection than for search.Examples, Dialogs, WizardsRetrieval by reformulation–Start with example queries•Rabbit, Helgon–Can be difficult to find appropriate starting queryWizards–Found to be helpful for users without necessary domain knowledge get through many step processes –Not helpful when wizard not accompanied with help–Not useful when goal is teaching how to use the interface.Guided tours–Presents a logical sequence of navigation choices for accomplishing a goal (e.g. Waldens Paths)–Not evaluated with regards to information accessAutomated Source SelectionSelecting collection automatically (but explicitly)Need a model of each collection–What it covers, need model of topics–What it is good at, need metric for goodDevelop a model of the user’s information needMatch the information need to the most valuable collections for that topicUsed in meta-search – interesting area of researchCould be starting point for interactive collection