CS/INFO 430
Information Retrieval
Lecture 22
Usability 1
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Course Administration
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Browsing:
The Human in the Loop
Return objects
Return
hits
Browse repository
Search index
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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
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Browsing in Information Space
Starting point
x
x
x
x
x
x
x
x
x
x
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Effectiveness depends on
(a) Starting point
(b) Effective feedback
(c) Convenience
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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
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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
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Browse: Catalog Record
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Browsing the Content of Indexes
Show the users the terms that occur in indexes, such
as subject headings.
Example: Library of Congress:American Memory
http://memory.loc.gov/
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Hierarchical browsing
Level 0
Level 1
Level 2
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Alphabetic list
http://nsdl.org/
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Broad
categories
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Subject
headings
grouped
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Subject
headings used
in index
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
http://cmi.rlg.org/
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Browse
everything
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Filter
"New York"
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Sort
"date"
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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
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Google
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Spacious
organization
AltaVista
Division of
functionality to
different pages
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ACM Digital Library
Emphasized
components
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ACM Digital Library advance Different
searchquery
insertion ways
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Yahoo!
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cramped
organization
The Old Yahoo! Interface
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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.
http://www.yahoo.com/
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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 ...
www.useit.com/papers/heuristic/ - 5k - Cached - Similar pages
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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
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Dynamic Return Hits
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Dynamic
snippets
Precomputed Return HitsPrecomputed
snippets
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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"
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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/...
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Dynamic Snippets
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Legal Information Institute www2.law.cornell.edu/.../doc/%7B@1%7D/
hit_headings/words=4/hits_only - 2k - Oct 27, 2003 - Cached -Similar
pages
DOC BodyPage
... Case Information. Brown v. Board of Education of Topeka . No. 1. ...
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
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Pre-computed Snippets
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Dynamic Snippets with
Pre-computed Summary
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Dynamic Snippets with
Pre-computed Summary
Pre-computer summary, with space for dynamic snippet
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Dynamic Snippets with
Pre-computed Summary
Complete record with dynamic snippet
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