Information Organisation


I’m back at uni. Two subjects this semester: Information Organisation and Information Provision.

A friend recently asked if she could borrow my lecture notes. And I realised I didn’t really have any. I’ve got the slides from the class, but no personal notes.

So I thought I’d start blogging some.

Last night’s class was Information Organisation. And we got thrown into the deep end, working with AACR2 and RDA and MARC 21. It was lots of fiddly detail and unfamiliar standards, made more confusing because I didn’t have a conceptual model of how these standards fit together.

So this is less my notes on the lecture than me trying to sort out the underlying concepts.


So people can find and use the information they need.

S. R. Ranganathan’s Fourth Law of Library Science: Save the time of the reader.



Physically, books and other items are stored in an order. The order is determined by a CLASSIFICATION SYSTEM – the two most common ones in use are the Dewey Decimal System and the Library of Congress system.

Browsing physical storage is slow and inefficient. To speed up searches, we create a CATALOGUE – a guide to the items in the collection.

Each item gets a RECORD. In the old days, this would be a physical card in the card catalogue. Each record contains FIELDS, and each field contains a VALUE.

(I may be imposing my Computer Science terminology on cataloguing here.)

In order to keep records consistent, there are CATALOGUING RULES (i.e. standards). These specify which fields to include and what format the values should be recorded in. This format is sometimes called the “punctuation”, as special punctuation is used to separate sub-fields.

With the move from card catalogues to computers, there was a need to create TRANSMISSION STANDARDS that make cataloguing standards machine-readable.

Diagram of the Cataloguing model

The Cataloguing Conceptual Model

(EDIT: The arrows here can be thought of a meaning “creates a need for…”. This is a conceptual relationship. The actual workflow for creating a record is:



AACR2 – Anglo-American Cataloguing Rules, 2nd edition

An international standard for many years. Superseded by RDA, because AACR2 doesn’t handle the new type of electronic resources well. But still in wide-spread use, because old standards never die.

RDA – Resource Description and Access

A new standard developed in 1997, and adopted in 2013.

Based on the Functional Requirements for Bibliographic Records (FRBR), the set of takss that a record should support.

RDA uses a hierarchical model of a resource:

  • Work: the distinct intellectual or artistic creation
    • Expression: the intellectual or artistic realisation of a work
      • Manifestation: the physical embodiment of a work (the version)
        • Item: a single, specific instance of the manifestation.


In the 1960s, there was a push to move cataloguing from cards to computers. As part of that, new cataloguing standards were created that were computer-friendly. These standards were called MARC (MAchine Readable Cataloguing).

There have been lots of different MARC standards, but we’ve settled on MARC 21.

MARC 21 is a TRANSMISSION STANDARD, since it’s a way of encoding the data from other standards into a machine-readable format.

A MARC 21 record is a series of lines, where each line contains the format:

  • TAG: a three digit number identifying the field
  • INDICATOR: two character code that contain field-specific special instructions
  • SUBFIELDS: multiple values that might be within a field
  • DELIMITERS: a special character that marks the start of a sub-field (usually | or $), followed by a single letter identifying the sub-field



Don’t try to remember all these values or formats. Look them up. Double-check.

“The needs of the user must come before the ease of the cataloguer.”- Sandford Berman, Radical Cataloguing (2000)




About davidwitteveen

IT person. Zine Maker. Level 0 Library Nerd. Doctor Who fan.
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