An appendix contains supplementary material that is not an essential part of the text itself but which may be helpful in providing a more comprehensive understanding of the research problem or it is information that is too cumbersome to be included in the body of the paper. A separate appendix should be used for each distinct topic or set of data and always have a title descriptive of its contents.
Tables, Appendices, Footnotes and Endnotes. The Writing Lab and The OWL. Purdue University.
Appendices are always supplementary to the research paper. As such, your study must be able to stand alone without the appendices, and the paper must contain all information including tables, diagrams, and results necessary to understand the research problem. The key point to remember when including an appendix is that the information is non-essential; if it were removed, the reader would still be able to comprehend the significance, importance, and implications of your research.
It is appropriate to include appendices for the following reasons:
Appendices. Academic Skills Office, University of New England; Chapter 12, "Use of Appendices." In Guide to Effective Grant Writing: How to Write a Successful NIH Grant. Otto O. Yang. (New York: Kluwer Academic, 2005), pp. 55-57.
I. General Points to Consider
When considering whether to include content in an appendix, keep in mind the following points:
II. Content
Never include an appendix that isn’t referred to in the text. All appendices should be summarized in your paper where it is relevant to the content. Appendices should also be arranged sequentially by the order they were first referenced in the text [i.e., Appendix 1 should not refer to text on page eight of your paper and Appendix 2 relate to text on page six].
There are few rules regarding what type of material can be included in an appendix, but here are some common examples:
NOTE: Appendices should not be a dumping ground for information. Do not include vague or irrelevant information in an appendix; this additional information will not help the reader’s overall understanding and interpretation of your research and may only distract the reader from understanding the significance of your overall study.
NOTE: Appendices are intended to provide supplementary information that you have gathered or created; it is not intended to replicate the work of others. For example, if you need to provide detailed information about the techniques of analysis used by another author in your literature review section, summarize that information, but use a citation to the original work. In this case, a citation to the work is sufficient enough to lead the author to the information you are conveying.
Format
Here are some general guideline on how to format appendices, but consult the writing style guide [e.g., APA] your professor wants you to use for more detail, if needed:
Appendices. The Structure, Format, Content, and Style of a Journal-Style Scientific Paper. Department of Biology. Bates College; Appendices. Academic Skills Office, University of New England; Chapter 12, "Use of Appendices." In Guide to Effective Grant Writing: How to Write a Successful NIH Grant. Otto O. Yang. (New York: Kluwer Academic, 2005), pp. 55-57; Tables, Appendices, Footnotes and Endnotes. The Writing Lab and The OWL. Purdue University; Lunsford, Andrea A. and Robert Connors. The St. Martin's Handbook. New York: St. Martin's Press, 1989; What To Know About The Purpose And Format Of A Research Paper Appendix. LoyolaCollegeCulion.com