Special Topics in Computer Science The Art of Information Retrieval Chapter 10: User Interfaces and Visualization Alexander Gelbukh

2 Previous chapter: Conclusions Inverted files seem to be the best option Other structures are good for specific cases oGenetic databases Sequential searching is an integral part of many indexing-based search techniques oMany methods to improve sequential searching Compression can be integrated with search

3 Previous chapter: Research topics Perhaps, new details in integration of compression and search Linguistic indexing: allowing linguistic variations oSearch in plural or only singular oSearch with or without synonyms

4 Topic Interfaces: Overview Human-computer interaction Search process Support for its parts: oWhat to start from oQuery specification oShowing the results oRelevance feedback Support for the whole process Many specific examples of systems oLong. Ill omit details

5 Human-computer interaction... Most important part of the problem oBad interface kills all the fancy technical features of a system. If you cannot use it, you dont care how good it is Chopsticks A good interface disappears -- like air Design principles oInformative feedback (e.g., relationships) Internal locus of control (= this feedback is customizable) oReduce working memory load (e.g., keep track) Permits to return to a temporally abandoned strategy oDistinct interfaces for novices / experts (simplicity vs power) Example: Google / Advanced search

6...Human-computer interaction... Bad interfaces -- Why? I think: Different weight of tasks for user and programmer Programmer: a list of (equal) tasks (functions) User: Goals. Some tasks are frequent and some not Example: Windows XP: oCopy, Print, Delete, publish in Web...

7...Human-computer interaction... Information visualization Humans are better at images than words Abstract info: more difficult. Interactive mode helps Types oBrushing and linking: different views of the same info; changing one changes others oPanning and zooming: Example: clustering. oFocus and context: fisheye camera oMagic lenses: temporally change a part of info under lens Combination: overview plus details oHierarchically

8...Human-computer interaction Evaluation What is evaluated: othe quality of final result (mostly precision, not recall) otime to learn the system otime to achieve goals oerror rates oretention of the use of interface over time People are very different: whats good for some is not for others Difficult to measure and evaluate

9 Information access process Goals. Tool. Tasks Basic interaction model: query result (repeat) Advanced models take into account: ointegration with browsing near-miss is acceptable: use hyperlinks oSelection of source collection oLearning while searching. Goal shift while searching oGetting the info by pieces, not as a set of relevant docs Temporal lateral goals, then return to the main goal Interface needs to support this

10 Not only search Search is a part of an activity on... Other tasks of this activity include ofinding trends, making comparisons oaggregating information, assessing, interpreting,... Search is intermitted with them, not a separate subtask Need for a common interface that supports the whole process. One tool.

11 Topic Interfaces: Overview Human-computer interaction Search process Support for its parts: oWhat to start from oQuery specification oShowing the results oRelevance feedback Support for the whole process

12 Starting points Choosing information source (collection) How to choose? Lists. Hard to guess Overviews: Panning and zooming oCategory hierarchies. Example: Yahoo! Large hierarchies need for good interfaces to navigate them oClustering Similarity measures: text, co-citations, co-links (Google),... Clustering on the fly. Summaries of the clusters. Zooming in. Clustering of search results (combination of search & navigation) Graphical views like stars or landscapes. Not clear if useful

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15...Starting points Examples oStart from some object and correct its desired properties oProblem: how to find from which one to start? Dialogues oModel a human librarian. Too complicated Wizards oOnly useful for simple tasks, not IR Guided tours Automated source selection oSearch in descriptions of collections. Or: meta-search

16 Query specification Types ocommand language?? (problem!), oform fillin, menu selection, direct manipulation, onatural language Problem: people have difficulties using Boolean expressions (e.g., confuse AND and OR) A lot of efforts to help the users to (visually) construct what is internally a Boolean query (cf. Bengts talk) oQuery preview helps

17 Presentation of results: context Documents by keywords Result list: document surrogates (detailed/not) oKWIC – key words in context (kind of abstract for query) oNow used for Web (e.g., Google) Full text oHighlight hits in full text oTilebars: representation of keyword distribution at a glance Keywords by documents Helps understanding which keywords are important

18... Presentation of results: context Organizing the query results oTable of Contents automatically generated trough hyperlinks oHyperlink structure oTables (but: only two attributes) too little improvement: TableLens

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22 Using relevance judgments Relevance feedback: control in terms of the task, not of the machinery that performs it (keyword weights) Degree of control (over the keywords to include) oControl only (users set the keywords) – worst, oopaque (reaction only), transparent (users see new words) openetrable: users have control over new words – best.

23 Interface for the whole program Example of problem: search window; old results versus newly typed query (not executed) Windows layout: monolithic (simple/little), tiled, overlapping (large/crowded). Workspaces. Persistent. Use the possibilities of windows obad example: Lexis-Nexis Provide history information. User preferences

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26 Research topics Many ideas throughout the chapter osome may be obsolete New interface types! 3D interfaces Ways of assessing the quality of interfaces

27 Conclusions Interface is a key element of the system. If the users cannot use it, it does not matter how good it is. Interface design choices are important at any stage of the process oEspecially to formulate queries oAlso to present results o3D interfaces to present results Also, overall system interface and action tracking Difficult to assess quality. Difficult to find new ideas Very promising if you find them!

28 Thank you! Till December 4 compensation lecture: December 11, combined with normal (last) lecture