In a message on Wed, 23 Nov 2005, Richard Urban
<[email protected]> wrote
2. Clustering/Collocation
Using a limited, controlled set of terms means it will be easier to establish
relationships between individual items and put like things next to each
other. This is more difficult when uncontrolled sets of keywords are used.
This is a point that I think should not be overlooked. There is a major
distinction between (1) a "post-coordinate" indexing system, in which
individual indexing terms are assigned to documents and not combined
until the searching stage and (2) "pre-coordinate" indexing, in which
terms are combined into strings at the indexing stage to express
compound concepts.
These two approaches are complementary, supporting searching and
browsing respectively, rather than conflicting.
1. Post-coordinate indexing, often using a thesaurus of individual
concepts, is effective for the retrieval of specific topics when
searchers know what they are looking for. Even though they do not know
the words the particular system uses to express these concepts, a good
thesaurus will provide entry points under any terms likely to be sought,
pointing to the terms that have been chosen as labels. Terms suggested
by users should be added to the vocabulary when likely to be sought,
either as preferred terms or non-preferred entry points. The problem
with uncontrolled "folksonomies" is that many different words may be
used for the same concepts, and someone searching using one word may not
find relevant information that has been labelled with a synonymous word.
2. Pre-coordinate indexing, such as LCSH or many classification schemes,
is of greatest benefit when the searcher wishes to review a subject area
by browsing in a catalogue or in an organised list of search results.
Someone searching for information on the steel industry may well find it
helpful to have the results subdivided and listed in order of the places
where the industry occurred (as in the previously cited example) or in
some other systematic order.
"Classification" may be defined as
"grouping together of similar or related things and the
separation of dissimilar or unrelated things and the arrangement
of the resulting groups in a logical and helpful sequence"
<http://www.willpowerinfo.co.uk/glossary.htm.
Let's have the best of both worlds.
Leonard Will
--
Willpower Information (Partners: Dr Leonard D Will, Sheena E Will)
Information Management Consultants Tel: +44 (0)20 8372 0092
27 Calshot Way, Enfield, Middlesex EN2 7BQ, UK. Fax: +44 (0)870 051 7276
[email protected] [email protected]
---------------- <URL:http://www.willpowerinfo.co.uk/> -----------------
---
You are currently subscribed to mcn_mcn-l as: [email protected]
To unsubscribe send a blank email to
[email protected]
