1 CS/INFO 430 Information Retrieval Lecture 23 Usability 1

2 Course Administration Assignment 4 Due Friday, December 1 Extensions only for exceptional circumstances

3 Usability Lectures Usability 1: Browsing and search interfaces Usability 2: Evaluation with human in the loop Usability 3: Usability design

4 Browsing: The Human in the Loop Search index Return hits Browse documents Return objects

5 Web Search: Browsing Users give queries of 2 to 4 words Most users click only on the first few results; few go beyond the fold on the first page 80% of users, use search engine to find sites search to find site browse to find information Amil Singhal, Google, 2004

6 Browsing in Information Space x x x xx x x x x x x x x x Starting point Effectiveness depends on (a) Starting point (b) Effective feedback (c) Convenience

7 Convenience when Browsing If documents are accessible online, user can browse content. Can compensate for weaknesses in the underlying search system, e.g., the difficulty of indexing Web documents Requires rapid delivery to the desktop Otherwise, the user can browse substitutes, e.g., catalog records, subject hierarchies, etc. Puts heavy demands on the precision/recall of the underlying search system

8 Browse: Catalog Record

9 Hierarchical browsing Level 2 Level 1 Level 0

10 Hierarchical browsing: collections

11 Alphabetical browsing

12 Alphabetical browsing: subject headings

13 Browsing the Content of Indexes Show the users the terms that occur in indexes, such as subject headings. Example: Library of Congress:American Memory

14 Subject headings used in index

15 Browsing by Filtering and Sorting Filters allow users to reject categories of information. Sorting by various criteria allows users to organize information for rapid scanning Example: Research Libraries Group Cultural Materials

16 Browse everything

17 Filter "New York"

18 Sort "date"

19 Snippets A snippet is a short record that a search system returns to describe and link to a hit. Example: Web search “Nielsen evaluation heuristics” Heuristic Evaluation... Jacob Nielsen's Online Writings on Heuristic Evaluation. How to conduct a heuristic evaluation; A list of ten recommended heuristics for usable interface design k - Cached - Similar pages

20 Usability of Search: Snippets Choices in designing snippets: Dynamic (generated from query + document) or pre-computed (from document only) Content only or with related information (e.g., subject hierarchies) Highlighting of search terms Length of snippet v. number on page User must understand why the hit was returned

21 Dynamic Return Hits Dynamic snippets

22 Precomputed Return Hits Pre-computed snippets

23 Pre-computed Snippets Legal Information Institute Brown v. Board of Education, 347 U.S. 483 (1954) (USSC+) 1. Syllabus, 2. Full Decision, 3. Syllabus & Opinions Only... www2.law.cornell.edu/cgi-bin/foliocgi.exe/... In general dynamic snippets are superior because they fit the user's expectations, but they can fail badly. Example: Web search " brown topeka kansas "

24 Dynamic Snippets Legal Information Institute hit_headings/words=4/hits_only - 2k - Oct 27, Cached -Similar pages DOC BodyPage... Case Information. Brown v. Board of Education of Topeka. No APPEAL FROM THE UNITED STATES DISTRICT COURT FOR THE DISTRICT OF KANSAS [*]. Syllabus.... www2.law.cornell.edu/.../doc/%7Bt26262%7D/ pageitems=%7Bbody%7D/hit_headings/words=4 - 13k - Cached - Similar pages

25 Pre-computed Snippets

26 Dynamic Snippets with Pre-computed Summary

27 Dynamic Snippets with Pre-computed Summary Pre-computer summary, with space for dynamic snippet

28 Dynamic Snippets with Pre-computed Summary Complete record with dynamic snippet

29 Designing the Search Page Making Decisions Overall organization: –Spacious or cramped –Division of functionality to different pages –Positioning components in the interface –Emphasizing parts of the interface Query insertion: insert text string or fill in text boxes Interactivity of search results Performance requirements

30 Google Spacious organization

31 AltaVista Division of functionality to different pages

32 ACM Digital Library Emphasized components

33 ACM Digital Library advance search Different ways to insert query

34 Yahoo! Cramped organization

35 The Old Yahoo! Interface

36 The Yahoo! Interface The Yahoo interface is cluttered and unattractive, yet Yahoo is one of the most successful of all web sites. Why is this interface successful? Very many branches from a single web page saves the need for hierarchy of menus. Simple html markup ensures that the page renders quickly and accurately on all browsers. Slow changes over the years means that users are familiar with it.

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