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Catalog Displays, Retrieval, and

FAST

May 31, 2005

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Overview Online Catalog Interfaces and

Subject Searching FAST: Faceted Application of Subject

Terminology

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Subject Searching in OPACs: Problem Statement Subject access can be provided via:

Controlled vocabulary• But users must discover the authoritative

terms themselves• Interfaces that assist users are more

effective than those that do not Natural language

• User must consider word forms, synonyms and homographs in constructing searches

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Subject Searching in OPACs: Solutions Authority control of subject terms Free text searching conventions

(truncation, Boolean logic, proximity searching)

Browsing Search facilitation

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Authority control of subject terms UF (4xx) or SA, NT, BT (5xx)

references direct users to authoritative or related headings

Scope notes may also be displayed Authority control works!

Wilkes & Nelson (1995): 75% of failed searches in catalog without authority control would have been successful with authority control

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Authority control of subject terms (cont.) Should catalogs direct users to the

correct form of headings?Or Should catalogs display the

appropriate entries directly?

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Authority control of subject terms (cont.) Problem: Users may not use the

terms in the controlled vocabulary Solutions:

1. Provide bibliographic instruction in subject searching

2. Make LCSH (or other thesaurus) available in paper or electronically

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Free Text Searching Truncation

User must consider all possible completions to a partial word entry

Example 1: librari? will retrieve librarians and librarianship, but miss library

Example 2: cat? will retrieve both cat and cats (desired result), but also catapult and caterpillar

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Free Text Searching (cont.) Boolean logic

Use of Boolean operators AND, OR, NOT Users need to understand how to use operators Users need to know what is in the database Example: Castles AND movies might retrieve works on

Irene and Vern Castle (American dancers) Research demonstrates that most users have difficulty

constructing effective Boolean searches Also, some catalogs do not explicitly inform users about

default operators Works best with instruction (online or training

sessions)

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Free Text Searching (cont.) Proximity searching

Can specify word order, words next to each other, words within a prescribed number of words of each other

Problems with free-text searching even with these techniques Lack of context Cannot account easily for foreign

languages

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Browsing Definition: Browsing is an exploration of a

database with the idea that something interesting or useful might be encountered following connections. (Olson and Boll)

Browsers can sometimes identify a specific purpose Some area(s) of interest begin(s) the search

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Browsing Pre-automation: browse in the shelflist Or find one or two items of interest in the

catalog, then continue the search at the shelf

Post-automation: browse an online shelflist Surfing the web is a type of browsing

activity!

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Search Facilitation Sophisticated search capabilities (such as

Boolean searching) are not used Help screens and screens with lists of

commands are also not heavily used Require the user to go to the help screens or

interpret the information

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Search Facilitation (cont.) Spell checkers Allow users to browse the

classification scheme if captions are included with class numbers

Tree structures based on subject headings

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FAST: Faceted Application of Subject Terminology LCSH is widely used and has been basis of

numerous other thesauri around the world Its application (constructing headings)

requires significant training FAST is an attempt to simplify the process

of assigning subject headings, but still use LCSH’s rich vocabulary

FAST is compatible with LCSH – can convert from LCSH to FAST

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FAST Design Be usable by people with minimal

training and experience, Enable a broad range of users to assign

subject terminology to Web resources, Be amenable to automated authority

control, Be compatible with use as embedded

metadata, Focus on making use of LCSH as a post-

coordinate system in an online environment.

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FAST Facets Six facets:

Topical Geographic Form Period Personal names Corporate names

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Examples Each facet is assigned in its own

MARC field:Blacksmithing $x Equipment and supplies California $z Los Angeles $z Hollywood $v Controversial literature $v Early works

to 1800

1900-1999

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Conversion of existing headings

650 0 Authority files (Information retrieval) $z Italy $z Florence $v Congresses.

Converts to:      Authority files (Information

retrieval)       Italy $z Florence Congresses

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Additional Simplification Characteristics Authority file permanently retains all

authority records Authority records are designated “obsolete”

rather than removed from the database Supports the linked structure of the file

All FAST records will be linked back to the LC authority record from which it was derived using 7xx linking fields.

Ongoing OCLC project: will hear more in the future