# Indexing and Abstracting Service in Library and Information Centers
## Learning Contents Summary

The contents of Indexing and Abstracting Service in Library and Information Centers as a learning resource is to expose librarians and library students to the concept of Indexing and Abstracting Service in Library and Information Centers and its types, Purpose of indexing and abstracting. This course material serves as an avenue for learners from diverse academic disciplines to acquire knowledge on how libraries and Libraries and Librarians understand the concept, Indexing and Abstracting Service in Library and Information Centers.

## Goals

At the end of this study, learners should be able to:
* understand the concepts of Indexing and Abstracting Service in Library and Information Centers,
* Identify the types of indexing and abstracting in Libraries and information center;
* Identify the theories and indexing language; and
* Identify purposes of Abstracting.

## The Concept of Indexing

Indexing an index is a systematic arrangement of entries designed to enable users locate information in a document. A document in this instance can be book, journal, audiotape, computer film and so on. However, a clear distinction between indexes to a book and indexes to a volume of journals is that while indexes to a book is an alphabetical list with page reference to a subject, persons and places dealt with within a particular book, indexes to journals or other periodicals indicate what articles have been written on subject, commentaries on a case, statutes, official reports or any other document. Indexing is the process of analyzing the content of an information resource and determining and expressing the "aboutness" of that item in a simple manner. Indexing is also concerned with characterizing the information resource in such a way that users are aware of basic document qualities such as author, title, length, and placement of the content.

### Principles of indexing Materials

i. Correctness or accuracy: This has to do with correct spelling and correct presentation of information in the index:
ii. Uniformity or consistency: Since indexing systems vary, indexer must adopt informing in indexing;
iii. Completeness: This simply complete bibliographic data
iv. Clarity: There should be specific and concise subject heading v. Consideration: This must use the language the user can easily understand.

## Functions of an index

An Index should perform one of the following
* identify and locate potentially relevant information in the document or collection being indexed;
* discriminate between information on a topic and passing mentions of a topic;
* exclude passing mentions of topics that offer nothing significant to the potential user;
* analyze concepts treated in a document so as to produce suitable index;
* use headings based on its terminology;
* indicate relationships among topics;
* group together information on topics scattered by the arrangement of the document or collection;
* direct users seeking information under terms not chosen as index headings to terms that have been chosen by means of see references.

## Indexing Language

Indexing language is composed of words or descriptors utilized in the intellectual contents of texts. The searcher is required to utilize these terms when looking for papers in the collection. Because the terms or concepts identified in a book are represented by words or phrases, the indexer and searcher must constantly employ an artificial language to describe a text. These indexing languages have been detailed in detail, along with their distinguishing features. we have two major types of indexing language which
* Natural Indexing language: The indexer uses the exact words and phrases used by the author of the document. This is very easy to use by the indexer and the searcher but the major problem is that there is no discrimination between synonyms, semantics, homographs, singular and plurals. This type of indexing tends to scatter documents on the same subject, where the authors have used different terms. The function of this type of language is to ensure that the indexer and the searcher operate at the same level by using the same language. This is to facilitate the retrieval of relevant information from the collection of the library. Natural indexing language is used mainly in the back of book index and computerized indexes such as Keyword in Context (KWIC) and Key Word out of Context (KWOC) indexes.
* Controlled Indexing Language: An indexer controls or executes the phrases that are used to represent subjects and are assigned to specific documents. The indexer has some control over the terms that will be used as index terms since the indexer assigns only phrases that have been identified as possible index terms. There is usually a predefined standard list of terminology to be used for a specific system. As a result, once an indexer has found terms that represent the document, he or she will review this standard list to ensure that the terms used are consistent. This standard list is divided into two categories. This list is sometimes referred to as an authority list. The first type is an alphabetical controlled list, in which the terms are sorted alphabetically.

## Pre -Coordinate and Post - Coordinate System

Subject indexing systems are roughly divided into pre-coordinate and post-coordinate systems. As previously stated, the primary goal of any indexing system is to represent the contents of documents using keywords or descriptors. In post-coordinate systems, one entry is created for each term chosen to represent the subject of a given document, and all entries are stored in a file. This phrase serves as the document's lead term. When a user submits a query, it is examined and some keywords that are reflective of the user's question are chosen. These query phrases are then compared to the index term file, and relevant documents are returned. Post-coordinate systems include Uniterm, Peek-a-boo, and others. As the name implies, keywords selected during the subject analysis stage are coordinated during the indexing step, and each entry represents the entire content of the document in question. Because the coordination occurs before to the user's search, this sort of indexing is known as "pre-coordinate indexing." PRECIS, POPSI, Chain process, Relational Indexing, NEPHIS, and other pre-coordinate indexing systems are examples. Thus, for a document discussing the application of computational linguistics to periodical indexing, entries prepared using any of the pre-coordinate systems will represent the full context in which the entry word occurs, whereas terms generated using the post-coordinate system are generated without any context. Unless all of the corresponding entries are found, the document's content cannot be learned.

## Concept of Abstracting

Abstracting is the process of examining the content of a resource and generating a concise summary or synopsis of that work. An abstract is not a work review, nor does it evaluate or interpret the work being interpreted. Despite the fact that it contains keywords and concepts from the main text, the abstract is an original work rather than an abridged portion. Users that need to stay current in their subject can do so by examining abstracts published in that discipline. Abstracts help readers decide which articles should be read in full and which can be skimmed or avoided entirely. Abstracts, according to librarians and other information workers, aid in the speed and utility of user searches. defines an abstract as a brief but accurate representation of the contents of a document and he opines that an abstract is different from an extract, an annotation or summary. An abstract can also be defined as a "summary" of the important contents of a work, usually an article in a periodical, by a professional other than the author, together with the specification of its original. As to who produced the abstract, Ashworth defines the term abstract as a précis of material, which in its narrower sense currently usually refers to the information contained in an article in a magazine, short booklet, or serial publication.

### Uses of Abstract

The following are uses of abstract :
* They enhance public awareness: Abstracts repackage the information included in the original document into a more compact form, making it easier to read and keep up to date.
* They save reading time: abstracts are much smaller in size in comparison to the original document, and yet can provide as much information as the user needs without going into the full text.
* Most abstracting journals cover more than one language, so the user can find out what studies and research have been published in languages that he or she cannot understand, and which are available.
* They increase indexing efficiency since they can be indexed considerably faster than original documents. Indexing rates can be increased by a ratio of two to four, and the cost of preparing the index is decreased with little or no loss of quality.