Concepts, or subjects, are the principal ideas represented or
discussed in a work. Conceptual analysis refers to determining what a
document is about and selecting concepts that will be of interest to
the potential community of users.
In determining the
subject content of a document, indexers should scan the text to ensure
that no useful information is overlooked. They should pay particular
attention to titles, summaries, tables of contents, chapter headings,
introductions and conclusions. Titles alone are usually insufficient
for determining the main subject content since titles of UN documents
are often very general or non-distinctive. The object of the document
is usually stated in the introductory sections, while the final section
generally states how far the aims were achieved; it is also important
to scan annexes and appendices, which often contain useful information
that is difficult to find elsewhere.
Indexers must select the concepts that best express the subject content of the document.
In addition to determining the main subject or subjects, the indexing process also involves determining
and selecting secondary concepts that may be useful in searching for specific information in UN documents
or for bringing out aspects of main concepts. In doing so, indexers should constantly bear in mind potential
users and the queries that may be put to the information system. They should ask themselves such questions as:
- Which concepts in the document might be interesting to users of the information system?
- How would users construct searches to find the document?
- Which indexing terms and combinations of terms would best anticipate their searches?
Of course, not all the ideas expressed in a document can be considered subjects. Some may be concepts that
are simply mentioned, or used only as examples.
Indexers should take care to avoid selecting words in the text that are only references or mentions
and not really subjects of a document, especially since users now have the option of full-text searching
in ODS for keywords that are not necessarily subjects of documents. Indexers should ask themselves such
questions as: Is this really a subject of the document, or is it only a reference or mention?
Would potential users find enough information to justify selecting this concept as a subject of the
In analyzing subject content and selecting concepts, indexers should always bear in mind three important
principles of the indexing process: exhaustivity, specificity and consistency.
Exhaustivity refers to the number of index terms assigned to all concepts mentioned in a document
or to the level of detail with which a given topic is treated. It is designed to improve the recall of
user searches, to ensure that a maximum number of documents relevant to a search are retrieved.
While there should never be an arbitrary limit to the number of concepts brought out, the optimum
level of exhaustivity depends on several factors, such as the type of work and the subject matter of
Exhaustive analysis is advisable, for instance, when a document deals with one of the UN's main
subject areas for which a very large body of documentation exists (such as development, human rights,
peacekeeping or international security), so that subjects are assigned for the various specific sub-topics
that would normally be brought out as primary subjects of other works.
The level of exhaustivity may also vary depending upon the type of document: for instance,
UN resolutions and decisions are analyzed at the highest level of exhaustivity, with subjects
assigned for each significant operative paragraph; substantive reports with chapters on different
sub-topics might have subjects assigned for each chapter; while procedural documents such as work
programmes or agendas, where the main subjects are corporate or conference names, would be assigned
a minimal number of topical subject terms (if any), and restricted documents that are not available
to most users would usually be indexed at a minimal level of exhaustivity.
This concept refers to how precisely the documentary language describes
the subjects and concepts in a document; its purpose is to ensure that
a maximum number of the documents retrieved in a search will be
relevant to the user. Concepts should be identified as specifically as
possible, that is, at least as specifically as the documentary language
allows and the purpose of the users allow. For example, a document on disarmament education would be
indexed with the term Disarmament Education, but not the terms
Disarmament or Education; a document concerning earthquakes would be
indexed with the term Earthquakes and not the broader term Natural
Disasters; documents on the work of the International Law Commission in
general would be indexed with the term International Law, while the
Commission's documents dealing with a specific topic such as diplomatic
protection would be indexed with the term Diplomatic Protection, not
the general term International Law.
Sometimes a topic can only be represented at the desired level of specificity by a combination of terms
available in the documentary language; for instance, the specific topic «multimodal transport operators»
is described by the combination of terms
MULTIMODAL TRANSPORT and TRANSPORT OPERATORS.
New terms may need to be introduced in the documentary language when works deal with topics
that are more specific than any existing terms (see also Part II, Term Selection).
Indexers should use judgement in applying
the indexing policy of specificity, bearing in mind the search requirements of
users. If a specific term is not likely to be known by many users and there is
not a cross-reference from a term that is likely to be used, indexers may
assign a broader term that is likely to be searched, in addition to the
Document concerning Maori:
650 17 $a INDIGENOUS PEOPLES
In this example, the indexer judges that users
might not know that MAORI is the term used for the indigenous people of New Zealand.
Since there is not a cross-reference from INDIGENOUS PEOPLES OF NEW ZEALAND–a term that is likely to be used–the
indexer assigns the terms INDIGENOUS PEOPLES, NEW ZEALAND
in addition to the narrower term MAORI.
650 17 $a NEW ZEALAND
650 17 $a MAORI
The quality of indexing can be measured in part by consistency. It is achieved through the agreed
standardization of the terms to be used to index a document. Each document should, of course, be
analyzed independently of its relation to other documents, so that no important subject will be
overlooked, and no subject irrelevant to the document at hand will be included. However, indexers need
to ensure that they are consistent in the approach taken to similar types of documents,
to documents in similar subject areas and in the concepts selected for a series of documents.
by the Department of Public Information (DPI), Dag Hammarskjöld
Library. Comments as well as suggestions for further
additions/enhancements may be directed to the Dag Hammarskjöld Library.
© United Nations 2005-2009. All rights reserved.
Last updated: 6 August 2012