Verbal Subject Analysis II: Periodical and Other Databases

Subject Cataloging vs. Indexing

• Both are related to the subject analysis of resources. 
• Subject cataloging  is a term used for the subject analysis operations in library cataloging. 
• Indexing is a term generally used for the subject analysis operations in various other resource organization contexts, including periodical databases and search engines. 

Brief History of Periodical Indexes

• Around the turn of the 20th century, the library community decided not to add article citations to the catalog. 
• This development led to the growth of the commercial indexing industry. 
• The result of this has been:
• Split files
• Fees for licensing database content
• Difficulty fulfilling Cutter's 2nd objective

Analytical Cataloging

• Analytical cataloging techniques are needed in order to provide access to the component parts of composite information resources, most commonly:
• Book chapters
• Proceedings articles (usually of academic meetings)
• Journal articles
• Definition from AARC2: Analysis is the process of preparing a bibliographic record that describes a part (or parts) of an item for which a comprehensive entry is made.

Analytical Cataloging Techniques

• Complex entries made within the record of composite work [cheap]:
• Analytical added entries:
• Use 740 tag for second of two works mentioned in title of item
• Note area for comprehensive entry of larger work:
• Use 505 tag for structured display of table of contents.
• Separate records created for the component parts of composite works ("In" Analytics)[expensive]:
• Use 773 to trace the component part record to parent record

Analytical Access to Journal Content

• Decision to not provide analytical access to journal content (i.e. directly to articles) was because of the expense:
• Excessive number of records would have to be created.
• Additional authority work would need to be done.
• As a result, through the 20th century, cataloging and periodical indexing/bibliography creation techniques evolved separate approaches. 

Overview Comparison

• Catalog
• Authority work
• Cataloging records represents the holdings of a library
• Periodical indexes:
• Subject indexes are extensive topical bibliographies (often include books and book chapters, too), usually covering large swaths of "territory"
• Domain-wide indexes (e.g. Index Medicus) attempt to capture an entire discipline (may include book chapters, too)
• No single library could ever own all items referred to in exhaustive bibliographies/indexes, thus leading to ILL (inter-Library Loan) services
• Authority work nonexistent (except controlled vocabularies)

Surrogate Records in Periodical Databases

• As is the case with library catalogs, periodical databases contain structured surrogate records. 
• This structuring is fairly consistent across periodical databases, both in terms of stored records (two part metadata model holds) and how records are displayed
• There is some authority control at work, but not in ways that you might think.

Collocation in Periodical Databases

• By subject - what about vocabulary control?
• By author - what about authority control?
• By journal - what about authority control?
• By language
• By publication type
• By date
• Etc., etc., etc. 

In all Collocation Contexts: MATCH!

• EXAMPLES:
• Indexers → author name → match ← author name ← users
• Indexers → journal name → match ← journal name ← users
• Indexers → vocabulary → match ←vocabulary ← users

Inverted File Structures

• How surrogate records are physically stored in the index of a database.
• Each surrogate record has a unique identifies (also called a pointer)
• Each word and phrase of the index has a record in the index; each record contains the UI for each surrogate record that contains that word or phrase:
• Dog: 235, 527; 5,345,672; 117,127,923
• Cat: 127; 2,753; 917,538; 327,543,238

How is Surrogate Information Stored?

• Print periodical indexes and bibliographies. 
• Online periodical databases:
• Examine sample database record for left side metadata elements
• Examine advanced search interface
• EXAMPLES:
• PubMed MEDLINE
• Library Literature
• ALWAYS KNOW THE START DATE OF YOUR ONLINE PERIODICAL DATABASE!
• Manual search of the literature is often needed for exhaustive searches
• Retrospective conversion of print indexes to online is not generally undertaken by database providers due to expense. 

Periodical Database Characteristics

• They usually hold more records than a library catalog.
• Information resources (i.e. journal articles) contain less information than the info resources in library catalogs and there are no detailed secondary navigation aids such as book indexes.
• More fields (i.e. left side elements) available for search word qualification.
• Important to distinguish database producing companies/organizations from database interface companies:
• Some companies/organizations provide both (e.g. PubMed MEDLINE)
• Other companies provide interface services, such as Dialog or EBSCO.

User Interfaces (UI) in Periodical Databases

• Common UIs employed in periodical databases:
• ISSN - uniquely numerical identification for individual serial publications
• Internal numbering systems within a periodical database, such as the PMID in MEDLINE (for known item searches)
• The most important UI is pre-Web and that is the "Address" of an article in the bibliographic universe (also known as the citation data) - also good for known item searches:
• Journal name
• Volume number (in some journals, the issue number also)
• First page number of article. 

Authority Control in Periodical Databases

• Titles - not controlled
• Authors - somewhat controlled:
• Indexers generally enter author name from the information resource
• Control rests with periodical editors, who often have policies on author names that may be different than other periodical editors
• Subjects - controlled:
• Controlled vocabularies are imposed across periodical  and over time by indexers
• However, subject searching is still subject to the problems associated with the "Great Pop vs. Soda Controversy"

Author Indexes in Periodical Databases

• Examine how author data is entered into surrogate records:
• Generally taken from the information resource in hand
• PubMed MEDLINE is an exception
• Some databases will provide lists of author names from which to choose:
• Indicator of authority work?
• Library Literature is an example
• Subject Indexing in Periodical Databases
• Indexing approach is "information access," therefore depth indexing is the general rule. 
• Indexers index to the most specific, therefore, hierarchies remain important in controlled vocabularies. 
• Pre-coordination and post-coordination are important concepts.

Subject Indexes in Periodical Databases

• Depth Indexing:
• General goal is to provide subject access to the information contained in an article.
• However, this practice is not universal across database producers; therefore, determine the depth of indexing of the database you are searching by examining existing records
• Be aware of the lag time related to subject indexing of articles

Management of Controlled Vocabularies

• Homonymy:
• Addressed by domain specificity of most periodical databases
• Various forms of qualification are used, including parenthetical, hierarchy, and scope notes. 
• New concepts:
• Literary warrant is generally not employed in periodical database vocabularies
• New terms are added after new concepts have established themselves in the literature
• This poses a challenge if you are searching at a "research front" (may need to perform a keyword search strategy of the abstract field)

Some Vocabularies for Periodical Databases

• MeSH
• NLM MeSH Browser
• PubMed MeSH Database
• Library Literature
• EBSCO interface

Other Controlled Vocabulary Contexts

• Getty Museum (the folks who created ULAN)
• Subject Terms (search "cubist")
• Thesaurus of Geographic Names (compare "Soviet Union" and "Russia")
• Dublin Core permits various subject vocabularies:
• Specification of subject element
• DC Vocabulary Qualifiers

Web Content for Human Indexing

• A-Z Web Indexes:
• MEDLINEPlus Topics A-Z (organizes access to Web-based information for patients)

Indexing in Context

1. Obtain information resource
2. Describe information resource in surrogate record
3. Subject analyze information resource in surrogate record:
• Verbal 
• Classification

Article Indexing Process

• Two steps:
• Analyze information resource to generate list of candidate concepts that describe its subject content
• Translate those concepts into the controlled vocabulary of the database
• ISO Standard for article indexing - special attention should be paid to certain sources of information:
• Title
• Abstract (when provided)
• Introduction; opening and concluding paragraphs
• Illustrations, diagrams, etc and their captions
• Words or groups of words that are underlined, bold, etc.