Page 188 - DLIS402_INFORMATION_ANALYSIS_AND_REPACKAGING

Unit 10: Pre-coordinate, Post-coordinate and Citation Indexing

Any system needs time for its testing and development with the introduction of a COMPASS, BNB Notes
stopped including LCSH headings until protests from the users finally led to their reintroduction in
1995. With the substitution of LCSH for COMPASS in 1995 the classified arrangement has no index
at all. As a result, BNB no longer shows any direct translation of the notations. The further
development in the application of the British Library subject system in online searching might be
possible once the necessary preconditions in the field of data and retrieval technology are created.

10.2 Post-coordinate Indexing System

It is a system in which information is organised under simple main headings but with devices whereby
the user can combine them to produce compound subjects. As the coordination of index terms is
done after the index files has been compiled, this indexing system is called post-coordinate indexing
system.
Indexing systems in which the combination of terms is not made during the indexing of the document
but during the searching in the database. Post-coordinate indexing systems are used in combination
with Boolean logic. Search sets are formed and combined with logic “and”.

The advantage using post-coordinate indexing is that single words may be combined,
which increases recall. The drawback is in particular the increased possibility of false
drops.

Example: Literature about “female alcoholics” is indexed using the terms “human females” and
“alcoholism”.
“Coordinate indexing” as a concept and as a method is founded by Mortimer Taube in 1951. He
defined is as “a method of analyzing items of information so that retrieval is performed by the
logical operations of the product, sum, and complement on the codes in the store”.
Examples
Examples for post-coordinate indexing system:
• Uniterm system of Taube dates about 1951
• Peek-aboo by batter in England and cordonnier in France by 1940.
• Edge-notched card system by calerin mooers
Features
1. None of the entries in the system are specific. There are relatively large number of
documents under each heading and if the searches approaches the index as a conventional
index, be in liable to become involved in extensive scanning of entries in order to
discriminate between relevant and less relevant documents.
2. There are usually a larger number of entries in a post-coordinate indexing system than in
an index based upon pre-coordinate indexing principles.
3. The number of different heading is the index is relevant small, because, as in classification
a system scheme needless categories or heading than an equivalent enumerative scheme.
Conclusion
Thus in indexing it has pre and post-coordinated indexing system. There have some similarity and
dissimilarities. It can be summed up as follows:

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