In a Book, what is an Appendix?

An appendix is a section at the end of a book that includes supplementary information that the author or publisher thinks may be of interest to the reader, but is either too tangential or too detailed to be worked into the actual text. Appendices are commonly used to support the qualifications of the author and to increase the credibility of the publication. They may also be used to help readers navigate the work, as is the case with an index or bibliography. In a book with multiple appendices, they are usually identified by letter, as in “Appendix A,” “Appendix B,” and so forth, and are often be paginated differently from the rest of the book.

All sorts of information can be included in an appendix. As a general rule, this portion of a book contains information that would not have been appropriate in the primary text, but is still important. For example, a book on natural childbirth might include an list of sources used and works which may be of additional interest to the reader — books from other cultures, for instance, or medical guides that may be beyond the scope of the author’s goals. This makes it easy for readers to get more information without requiring the author to touch on absolutely everything.

Raw data is frequently presented in the appendices of scientific and scholarly works so that people can see immediate sources for themselves. Tables, charts, and graphs are common here — these elements are important, but are often seen as overly distracting when placed directly in the body of the text. Including these elements at the end is a good way to make sure that they are accessible. Failure to include raw data can lead to censure or questions about the credibility of the analysis. In the eyes of some readers, the only reason to omit data is to cover up bad research or poor methodology.

Many works also include an index or itemized references to specific topics in the book. Cookbooks, for instance, commonly have an index of recipes by ingredient so that someone who wants to look up a recipe using onions can flip to “onions” in the index and see which pages of the book contain onion recipes. Most of the time, recipes are sorted by title as well in order to give maximum flexibility.

Indexes may also be arranged by topic, individual, or main idea. This sort of organization is particularly useful for readers who want to be able to refer back to something they remembered enjoying or are wanting to know more about. Glossaries are another thing commonly found in appendices — these are resources that define terms used in the text, usually with a page reference to where the word, term, or person named can be read about in more depth.

An appendix can also include first hand sources like letters, photographs, cargo manifests, and other original documents in works of research. Bibliographers are fond of including this kind of information for their readers, often because they find it intriguing but may not have had the time to go over it in detail. It is also possible to find references like maps and technical drawings in this area.

Some style guides recommend including footnotes or endnotes in an appendix rather than in the text itself. This can reduce distraction, and also gathers footnoted information in one convenient spot rather than forcing readers to flip back and forth between numerous pages to consult different sources.

A book appendix should not be confused with the vermiform appendix, which is a vestigial organ found in humans. Many believe that the book appendix was named after the organ, in that neither is truly essential: humans can live without their appendices just as books would be complete without the supplemental materials, guides, and indices included at the back.