We all agree that an index adds extra value to any document. It provides easy access to certain information contained in a book or any given text. An index also makes effective information retrieval possible by successfully minimizing the time and effort required by the reader to find what they’re looking for.

An index is a sign of quality that allows potential users to decide whether or not a specific book may be suitable for them. Therefore, a relevant book index at the end of a book increases its sales.

Usually, when we think about indexing, book indexing is the first thing that comes to mind. However, this is just one of many types of indexing.

What’s more, there are different ways to categorize types of indexes too. Here we have chosen to list some common types of indexes according to the nature and format of the document being indexed.

Some of the most popular types of indexes are as follows:

Database Indexes

Simply put, the primary purpose of a database index is to provide a map to relevant data. Usually, this type of index is made for public data, such as journal articles.

In this case, the indexer’s task is to describe a document and highlight where to look for specific info according to different rules applied to a given database. Medical or scientific journal articles are types of text where this type of index can be found. Through the database, any user should be able to access the full text online. An abstract briefly explaining the content of the documents is also a part of database indexes.

Book Index

An index in the back of all non-fiction books is a must. It’s a vital part of every textbook, different kinds of reports, and multi-volume works.

Even though we all know what a book index is and we can easily recognize it, it’s hard to define. Different types of books require unique approaches and techniques.

eBook Indexing

eBooks, PDF books, and, in general, all the books accessible online should also have indexes.

Just like an index in a printed book, an ebook index also represents an alphabetical list of subjects covered in the text. Instead of having a page number, it’s preferable to add hyperlinks that will lead directly to the part of the text where certain information is stored.

Geographical Index

Geographical indexing requires special skills, such as solid backgrounds in geography and cartography. This type of index is usually created for atlases, maps, and some other cartographic material.

Geographical indexes may include historical, cultural, artistic details, and mathematical coordinates, etc.

Genealogical Indexing

The main purpose of genealogical indexing is to help people find all kinds of information about people, including personal data and their family relationships. They exist so that the person who’s searching for such information doesn’t have to dig through original source materials and archives.

Newspaper and Periodical Indexing

There are two different types of newspaper and periodical indexes: annual and cumulative. The main purpose of these types of indexes is to help you find articles about a specific topic. Simply put, newspaper and periodical indexes are conceived as a catalogue of subjects for articles you can find in specific magazines and journals.

Legal Indexing as a type of Indexing

As the name suggests, a legal indexes are compilations of law-related articles or reviews. The index entries are organized by the name of the author, title, and subject. This type of index can be a handy tool for quickly finding articles covering law topics. Of course, legal indexing requires special skills, and the indexer must be familiar with legal concepts.

Pictorial Indexing

Pictorial indexes describe both still and moving images. Photos, slides, films, and videos are analyzed and then introduced into a pictorial index.

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