Indexing languages help users discriminate between terms and reduce ambiguity. They consist of controlled vocabularies and rules for their use to assist both indexers and searchers. Indexing languages provide consistency in indexing and searching through the control of synonyms and specification of related, broader, and narrower terms.

1. INDEXING LANGUAGES

2. Any vocabulary, controlled or uncontrolled used
for indexing ,along with the rules of usage.
Is much more than a list of index terms that are
acceptable to users.

3.  Helps users discriminate between terms and
reduces an ambiguity in the language.
 To assist both indexers and searchers in using
and manipulating the system.

4.  Assigned term
 Derived term

5.  An indexer must assign terms or descriptors on
the basis of subjective interpretation of the
concepts implied in the documents.
 The indexer determine the subject matter of the
document at hand.
 Assigned descriptors from a controlled
vocabulary, which identifies concepts
expressed by the documents author.

6.  All the descriptors are taken from the text itself.
 Sometimes called natural language or free text
indexing.

7.  Is a related group of words or phrases adopted
by a particular group of people to be used in an
indexing activity.
 Formal lists of the words in the controlled
vocabulary.

9.  Evolutionary vocabulary
- consists of raw material supplied by indexers.
- Which is edited or planned after the fact.
 Enumerated vocabulary
- Is generated as the result of a special study or
inquiry and a consensus of experts who
predetermine what the vocabulary should be
for an area of knowledge.

10.  Show vertical arrangements of words within
classes.
 Indicate synonymous relationships, near
synonymous relationships and related word
groups.

11.  Specific language, with words, relationships of
words and its own grammatical rules for
usage.
 It is a controlled , collected subset of natural
language.

12.  Consistency in indexing and searching.
 The control of synonyms, although it has many
other functions such as related words, more
specific words and broader words.