Subject Access: Indexing and Abstracting Spring 2006, 27 March Bharat Mehra IS 520 (Organization and Representation of Information) School of Information Sciences University of Tennessee

Exercise 3: Authority Control OBJECTIVES to observe name authority control to observe controlled vocabulary for subject access Part I. Name authority Go to the authority record database in Library of Congress http://authorities.loc.gov/. Search for the popular author, Samuel Clemens. How many authorized headings are established for him? Attach the most complete MARC Authority record for each authorized heading. For the MARC Authority format, explain the semantics (meanings) of the fields: 1xx, 4xx and 5xx. Make sure that you mention how authorized and unauthorized headings are cross-referenced. For each authorized heading, how many bibliographic records are found in LC collection using the heading? If an authorized heading is not used, why so? Can the user just click on the authorized heading to retrieve bibliographic records by the author?

Exercise 3: Authority Control Part II. Authorized subject headings Go to the authority record database in Library of Congress http://authorities.loc.gov/. Search for an authorized subject heading for each of the topics: Teapot Dome scandal Watergate scandal What are the broader heading (BT)? What are the narrower headings (NT)? What are the related headings (RT)? Construct an alphabetical subject headings list of the headings (BT, NT, RT, the heading itself) and their related headings including both authorized headings and lead-in terms. Under each heading cross-reference the related terms: Used-for, Use, BT, NT, RT.

Exercise 3: Authority Control WHAT TO TURN IN? The authority records for Samuel Clemens in MARC format and your answers to all the questions. The authority records for the two subject headings in MARC format and the subject headings list. A brief discussion on the roles of authority control in IR.

Why Abstracting and Indexing? Abstracts represent content of documents concisely -- a representation tool Indexes facilitate locating information efficiently -- a retrieval tool

Abstracting and Indexing Construct representations of published items (subject matter of documents) in the form suitable for inclusion in a searching system Abstracts help in summarizing: narrative description Indexes identify the subject: describes documents contents via index terms

Why is the Distinction between Abstracting and Indexing Getting Blurred?

Functions of Abstracts A well-prepared abstract enables readers (a) to identify the subject and basic content of a document quickly (b) to determine its relevance to their interests (c) to substitute the original document (e.g., lack of physical access or language skill, etc.)

Standard for Abstracts: Z39.14 Terminology (rule 3) Content elements (rule 6.3) Length (rule 7.1) Single paragraph (rule 7.2) Use complete sentences (rule 7.3) Use active verbs (rule 7.5) Terminology -- avoid jargon (rule 7.6) Illustrative examples are given in appendix

Abstract vs. Extract Abstract -- a brief and objective representation of a document written by the author or an abstractor; generally a single paragraph of text Extract -- one or more portions of a document selected to represent the whole; out of original document

Types of Abstracts Indicative abstract it describes the purpose or scope of discussion or descriptions; or essential background material, the approaches used, and/or arguments presented Informative abstract serves as a condensed original document; it states (1) purpose (2) methodology (3) results, (4) conclusions (5) others if applicable

Types of Abstracts (cont) Structured abstract (informative) with prescribed headings (e.g. Medline) objectives, design, setting, patients, measure, results, conclusions For examples of structured abstract, search the MedLine at http://www.ncbi.nlm.nih.gov/entrez/query/static/citmatch.html

Indexes Index -- a systematic guide designed to indicate TOPICS or features of documents in order to facilitate retrieval of documents or parts of documents (identified by the author) Structure of an Index list of entries (headings or terms) and locators/pointers; syntax in display; cross-references; arrangement

What Factors Determine Subject Indexing? What the document is about? Why has it been added to our collection? What aspects will users be interested in?

Technology for Retrieval Index files one master file (that sequentially stores all bibliographic records) -- linear master file many index files (each file indexes only one type of access points) -- inverted indexes

Linear Master file

Inverted indexes Author Subject Chan, Lois Mai 87009368 88009087 Pollard, Richard C. Subject Cataloging/Teaching 87009368 Information/Directory 88009087 Surveys/Library Science literature Textbooks Thesauri/Bibliography

How are Inverted Files Created? (Hearst & Larson, 1998) For example, identify the term (a, and, come, country…), the document number in which it occurs (1, 2), and the frequency of occurrence? Inverted files permit fast search for individual items for each term, you get a list consisting of: document ID frequency of term in doc (optional) position of term in doc (optional) These lists can be used to solve Boolean queries country  d1, d2 manor  d2 country AND manor  d2 Used for automatic indexing and statistical ranking algorithms

Post-Coordinate Indexes

Processes of Indexing Conceptual analysis: “aboutness” Translation: use of controlled vocabularies via Subject heading lists or Thesauri Indexing by Extraction (Derivative Indexing) Assignment Indexing Differences between: Subject cataloging Subject indexing Subject classification

Issues in Indexing Indexing policy Indexing accuracy Conceptual analysis and Translation Exhaustivity (depth) Specificity Example: architecture of cathedrals ecclesiastical architecture + cathedrals domestic architecture

Citation Indexes A database for citation searches The main access points in a citation index are cited authors, cited works, and/or cited references, cited year Citation counts have been used to evaluate influences of authors and their works in a field

Links as Subject Access Tool Citation links: from known works to their citations (intellectual networks) Hyperlinks of certain fields in search results: subject headings Relevance feedback: automatic expansion of searches for additional documents like the selected documents

Indexing of Images (Layne article) Image indexing based on attributes of images should provide access to groupings of images Attributes of images: Biographical, Subject, Exemplified, Relationship Important issues when creating groupings of images: When should grouping occur? What are the groupings based on? What level of detail is necessary? What groupings will be useful? To whom?

The challenges of subject access to non-textual info objects How do we search for known items that are image/music? What are the attributes for describing image/music in IR? What are the unique attributes for searching image/music in IR? How do users search for unknown image/music (subject access)?

Access to images biographic birth (creator, time, place, & title) travels (where, who, price, alteration) subject of-ness about-ness

Subject Access to Images Panofsky’s 3 levels of meaning in images pre-iconography -- of-ness iconography -- about-ness iconology – interpretation Images -- description vs. interpretation

Of-ness About-ness Interpretation

Music facets Symbol facets: lyrics, editorial, bibliographic Audio facets: pitch, temporal, harmonic, timbre

Access to music Text/symbol-based Audio-based Bibliographic (title, composer, lyricist, genre, lyrics, etc.) Event (performer, instrument, date, place, …) Audio-based Melody (querying by humming/singing) Music incipit (encoding according to Plaine and Easie Code to represent pitch (alphabet) and duration (numeric))