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AUTHORITY CONTROL

Chapter 2. AUTHORITY CONTROL

   

 

CASCADE

CASCADE checks selected eligible headings (tags 110, 130, 600, 610, 630, 650, 710) for matches using the entire heading field from the bibliographic record. If a match is not found, CASCADE drops the rightmost subfield and repeats the check. If a match is still not found, CASCADE continues to drop the rightmost subfield, one at a time, until a match is found or until only the lead element (subfield or group of subfields) remains. CASCADE performs the following actions for each applicable heading:

  1. Normalization of Bibliographic and Authority Headings

    All diacritical characters, punctuation, upper- and lower-case character distinctions, MARC subfield designators and extra spaces are temporarily removed from the bibliographic and authority headings for matching purposes.

  2. Selective Validation of Tags for Compatibility

    The field in which the heading is coded in the bibliographic record is compared with the appropriate fields in the authority records (refer to Bibliographic Heading Validation Matrix for a listing of eligible bibliographic headings fields and subfields, and the authority headings fields against which they are validated).

  3. Comparison of Subject Headings

    The value in indicator 2 of bibliographic record 6xx tags is matched against the thesauri listed in the Subject Heading Validation Matrix.

    • If the text in subject headings in the bibliographic record and the text in the authority record do not match, validation does not occur, and the message “No Headings Matched” displays following the subject heading in the bibliographic record, as shown in the following example.

      Example:

    650    *1  a Time travel v Fiction. No Headings Matched

  4. Authority Record Type Verification

    The code in the authority record 008 tag, position 9, is checked to ensure the heading in the 1xx tag is an established heading (008 tag, position 9 is either blank or coded “a”).

    • If the code in the 008 tag, position 9 indicates the heading in the 1xx tag of the authority record is an established heading, a link is automatically made between the authority record and the appropriate heading field in the bibliographic record; otherwise, validation does not occur, and the “No Headings Matched” message displays following the subject heading in the bibliographic record.
  5. Conflicting AGCNs Check

    If two or more records from the same source agency contain the same text in either the 1xx or, more commonly, the 4xx tags, the message “Conflicting AGCNs”, followed by the AGCN for each of the conflicting records, displays beneath the applicable subject heading in the bibliographic record. You must evaluate each conflicting AGCN to determine and select the authority record against which you wish the bibliographic record to be validated (see Working with the Validated Record for details).

    Example:

    650    *1  a Plays 9 Conflicting AGCNs: [1039975]|ALINK1, [4296724]|ALINK2 (KIDS) x Juvenile fiction.

  6. Preferred Heading Check

    Matching headings may be found as either the preferred form (in the 1xx tag of the authority record) or as a see from reference (in the 4xx tag of the authority record). The bibliographic record heading is checked to determine if the heading matched the preferred form or the see from reference of the heading in the authority record. If the bibliographic heading matches the preferred form or the see from reference, the text in the bibliographic heading is replaced with the preferred form from the authority record.

    • The validation message includes the AGCN of the authority record against which the heading is validated, a code representing the owner of the authority record, the tag of the authority record heading which matched the bibliographic heading and the message “VALIDATED.” Subfields that were not validated are shown following the “VALIDATED” message, in boldface type. The AGCN in the validation message also provides a link to the associated authority record.

      Example:

    650    *1  a Schools [AGCN:1040019] KIDS:150 VALIDATED x Juvenile fiction.

  7. Drop Rightmost Subfield (Cascade)

    If a match is not found, the rightmost subfield of the bibliographic record heading is dropped and validation steps 1 through 7 are repeated. The cascading process is repeated until a match is found, or until only the lead element of the bibliographic field remains (see Bibliographic Heading Validation Matrix for a description of lead elements of bibliographic fields eligible for processing).

NOTE: Fields that produce a “VALIDATED” or “Conflicting AGCNs” message are not subjected to further processing using the VERI and VERILEAD functions.