draft writing

   

3. Access and authority control

Access points are often under some form of authority control (also called access control or terminology control). Authority control is a mechanism for bringing consistency to data values in an information organization system. Data entered in fields that are under authority control must come from a file or list of authorized (or controlled) terms. In your system, terms related to subjects and to names of people and corporations are under authority control. You can establish authority control in two forms for purposes of this assignment:

 

· thesaurus (external to the main database file) for subject terms (section 4.2, required)

· name authority file (external to the main database file) for names in the records (section 5, required)

 

In this section, you explain authority control in general and state which fields are under which type of control.

 

Tasks: Determine which fields (both physical description and subject description) are under some form of authority control.

Consider the following:

· Fields with simple, predictable terms. These are usually physical description fields such as Format with terms such as "book" and "video." Decide whether any such field should be under control of a controlled vocabulary

· The field with the greatest number of potential terms and the most semantically (conceptually) complex terms, especially how the terms are related to one another is a candidate for a thesaurus. Usually this is a subject field. Choose one field only for vocabulary control using a thesaurus.

· Fields with proper names. These may be personal names (people) or corporate names (companies, organizations). Usually all name fields are controlled by a name authority file. The name authority file also controls the form of names used in subject fields.

 

Write narrative.

 

Narrative:

· Discuss the purpose of authority control and its importance in your system.

· Explain how it works.

· Explain the relationship to controlled vocabularies.

· Explain why it is beneficial to have specific access points under authority control from the perspectives of the end user searching the system and the technical user creating the records.

· State the kinds of authority control in your system.  Note that access points do not always have to be under authority control, and you can have authority control on non-access points.

· Discuss the fields under control of a thesaurus, and a name authority file. State explicitly which fields are under which type of control mechanism.

 

Hint: If you have trouble completing this section, come back to it after completing section 4.

4. Representation of information content

 

Given the basic resource description for the information container developed in section 2, you now need to determine the metadata elements necessary for representing information content (or intellectual content, subjects, topics). Section 4 focuses on problems of describing subjects, including use of controlled vocabulary in section 4.2, and subject-based classification in section 4.3.

 

4.1. Subject access

 

Tasks:

· Determine how to provide subject representation, or how to represent the information content of the objects.

· The subject representations will be the basis for providing subject access in your system.

· Consider the kinds of subjects (e.g., topics, themes, time period, geographic area) of the information objects.

· Note that, although fields such as title and table of contents can provide clues to aboutness, these fields are considered physical description of the information container, not subject description of the information content.

· Decide how many subject fields you need.

· You may translate Subject into more than one field (e.g., Topics and Time Period) and/or you may rename the metadata element and database field.

· You may have some subject fields controlled by a subject heading list, or controlled by a thesaurus, or fields that contain natural language terms (e.g., abstracts, summaries, etc.).

 

The classification code to be developed in Draft 3 should be based in part on information content.

Narrative:

· Define and discuss subject representation, subject analysis and subject access.

· Explain the importance of subject access for your users.

· Describe how your organization system provides subject access by listing all fields in your records that contain subject-related data or information.

· Explain that classification is partially based on subject, identify the subject-based facet(s) in your classification scheme, and name the field that contains the classification code. (You may need to return to this after you complete section 4.3).

 

4.2. Thesaurus structure

 

This section addresses subject authority control (also called vocabulary control or terminology control) using a thesaurus. A thesaurus is a list of controlled vocabulary terms that provides data values (terms) for a single field under subject authority control. It serves both technical users (indexers, cataloguers) as a source of terms to enter in the record and end users as a source of search terms.

 

Tasks:

· Review the Thesaurus Tutorial in the Canvas course site.

· Review, discuss and demonstrate the three semantic (conceptual) relationships in the thesaurus, and understand how mandatory reciprocals are used to indicate these three relationships.  This should be a thorough discussion that fully informs the readers on this topic.

· Determine the domain and scope of the thesaurus.

· Make decisions concerning specificity and exhaustivity.

· Consider how each decision may affect information retrieval performance based on measures of precision and recall.

Write narrative.

 

Narrative:

· Explain the purpose of subject authority control, how it is implemented in your system, and why it is important for both end users and technical users of your system.

· Discuss why the subject field needs authority control

· Define the thesaurus as a kind of controlled vocabulary. Explain the purpose of its syndetic structure.

· Define and describe the three (3) kinds of semantic relationships and how each is displayed.

· Explain mandatory reciprocals and how they are used.

· Describe the domain and scope of the thesaurus.

· Define specificity.

· State the level of specificity in the thesaurus (high, moderate, low) and explain why it is appropriate for the users and/or information objects.

· Discuss the probable effect of this level of specificity on precision and recall measures of information retrieval performance.

· Define exhaustivity. State the level of exhaustivity for indexing, that is, whether the indexer should tend more toward depth indexing or summarization.

· Explain why this level is appropriate for the users and/or information objects.

· Discuss the probable effect of this level of exhaustivity on precision and recall measures of information retrieval performance.

Refer to Appendix D: Sample thesaurus.

 

Note: The instructor understands that your thesaurus is only a sample and that it is not comprehensive. The reader should have a thorough understanding of how a thesaurus works, how the three relationships work, how they look in the thesaurus, what mandatory reciprocals are, and how they are shown in the thesaurus.  Actual examples go a long way here.

 

4.3. Classification scheme

 

Classification is a process of categorizing objects according to one or more attributes or characteristics. Formal classification systems such as Dewey Decimal and Library of Congress are called schemes. Classification codes are derived from schemes and assigned to objects to group items that are similar in one or more ways together. The primary function of bibliographic classification is to bring items together that contain similar intellectual content or subject matter. In the library world, bibliographic classification systems are also used as the basis for physical location. Classification schemes are used by technical users who create the codes and by end users who want to understand the organization of materials.  Ultimately, your classification codes will be your call numbers.

 

Tasks:

· Review Faceted Classification Tutorial and/or Hierarchical Classification Tutorial in the Canvas course site.

· Determine your approach to classification: faceted (recommended) or hybrid (hierarchical first facet) .

· Choose three or four attributes of the objects (e.g., subject, creator, literary form or genre, media format, date) to be used in classification.

· Consider attributes suggested by users' questions and how these relate to users' expectations for physical arrangement of objects (e.g., whether to arrange objects first by subject or by format).

· For this project, you should have at least three (3) facets, and at least one (1) facet must relate to information content or subjects.  Your first facet should not be Author or any other facet that merely alphabetizes the collection. 

· Develop a notation code (you may not use a pre-existing code such as Dewey or LC) to identify and group the objects by class.

· In order to physically organize the objects, make this a unique identifier (call number) by adding to the notation code a unique number (for example, RecordID) to identify the individual object.

· Be sure to create a code (call number) for each of your records.

Create Appendix E: Classification scheme.

 

Write narrative.

Narrative:

· Define classification and its purposes in general.

· Describe the role of classification in your system with regard to providing intellectual access and physical access if appropriate.

· Define and describe the difference between faceted and hierarchical approaches to classification; state your approach and explain your choice. The reader should have a thorough understanding of the differences, pros, cons, etc. of each.

· State the primary facet and explain why you chose it with regard to providing intellectual access (subject-based). List the other facets in order.

· Explain why you chose these facets, including their effectiveness as a system for intellectual and physical organization of the objects (if applicable). 

· Your primary facet should be derived from a field that uses a controlled vocabulary.

· If you are adding a unique identifier to the classification code for physical arrangement, explain why that is necessary and the source of the unique identifier.

· In a separate paragraph, illustrate your classification system by providing a complete example of one classification code:

· Briefly describe one of your 10 objects

· Show the classification code for that object

· Explain what each part of the classification code represents.