1. CS/INFO 430 Information Retrieval
Lecture 22
Usability 1

2. Course Administration

3. Browsing: The Human in the Loop
Return objects
Return hits
Browse repository
Search index

4. 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

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

6. Convenience of Browsing
Rapid access to materials
Physical objects
• Library or large private collection
• Similar items stored close together (classification)
Online information
• Rapid delivery to desktop
good system performance
no administrative delays (authentication)
Human skills and knowledge augment and extend the automatic methods of searching

7. Convenience of Browsing
If the documents are accessible online, user can browse content.
• This can compensate for weaknesses in the underlying search
system, e.g., the difficulty of indexing Web documents
Otherwise, the user can browse substitutes, e.g., catalog records, subject hierarchies, etc.
• This puts heavy demands on the precision/recall of the
underlying search system

8. Browse: Catalog Record

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

10. Hierarchical browsing
Level 0
Level 1
Level 2

11. Alphabetic list

12. Broad categories

13. Subject headings grouped

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. 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

20. Spacious organization
Google
Spacious organization

21. Division of functionality to different pages
AltaVista
Division of functionality to different pages

22. Emphasized components
ACM Digital Library
Emphasized components

23. ACM Digital Library advance search
Different query insertion ways

24. Yahoo!
cramped organization

25. The Old Yahoo! Interface

26. 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.

28. Return Hits: 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

29. Usability of Search: Snippets
Choices in designing snippets:
• Dynamic (generated from query + document) or precomputed (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

30. Dynamic Return Hits
Dynamic snippets

31. Precomputed Return Hits
Precomputed snippets

32. Pre-computed Snippets
In general dynamic snippets are superior because they fit the user's expectations, but they can fail badly.
Example: Web search "brown topeka kansas"
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/...

33. 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= k - Cached -Similar pages

34. Pre-computed Snippets

35. Dynamic Snippets with Pre-computed Summary

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

37. Dynamic Snippets with Pre-computed Summary
Complete record with dynamic snippet