1 CS/INFO 430 Information Retrieval Lecture 23 Usability 1.

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CS/INFO 430Information Retrieval

Lecture 23

Usability 1

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Course Administration

Assignment 4

• Due Friday, December 1

• Extensions only for exceptional circumstances

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Usability Lectures

Usability 1: Browsing and search interfaces

Usability 2: Evaluation with human in the loop

Usability 3: Usability design

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Browsing: The Human in the Loop

Search index

Return hits

Browse documents

Return objects

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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

x

x

xxxx

x

x

x

xx

x

x x

Starting point

Effectiveness depends on

(a) Starting point

(b) Effective feedback

(c) Convenience

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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

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Browse: Catalog Record

QuickTime™ and aTIFF (LZW) decompressorare needed to see this picture.

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Hierarchical browsing

Level 2

Level 1

Level 0

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QuickTime™ and aTIFF (LZW) decompressor

are needed to see this picture.

Hierarchical browsing: collections

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Alphabetical browsing

http://nsdl.org/

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are needed to see this picture. Alphabetical browsing:

subject headings

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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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Subject headings used in index

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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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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 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

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Dynamic Return HitsDynamic snippets

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Precomputed Return HitsPre-computed

snippets

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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"

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Dynamic Snippets


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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Pre-computer summary, with space for dynamic snippet

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Complete record with dynamic snippet

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Designing the Search PageMaking 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

Spacious organization

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AltaVista

Division of functionality to different pages

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ACM Digital Library

Emphasized components

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ACM Digital Library advance searchDifferent ways to insert query

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Yahoo!Cramped

organization

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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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1 CS/INFO 430 Information Retrieval Lecture 23 Usability 1.

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