This can apply to anything from lengthy quotations and long lists to detailed procedures and excessive raw data.
The second question to be answered when preparing to write an appendix is this one: Is it more helpful for the reader that this information be included in the main text or placed in a separate section?
An appendix is an addition to the main text, but this does not mean that it serves as a repository for essential information that cannot be conveniently placed within the main text.
The main text should always be complete in itself and the central argument be supported within the main text, as if the appendix were not there at all.
Each type of material added should be added as a new appendix and each separate appendix should be labelled or numbered, for example, Appendix A or Appendix I.
It is also useful to name the appendix with a descriptive title, for example, 'Appendix A: Raw Data.' Appendices are normally placed at the end of a document before the notes or references, or sometimes at the end of a chapter in a book and always included, with a page reference, in the Table of Contents.The reader should then be given a solid summary within the main text and a reference to the appendix where the material is available in full.When writing an appendix, deciding how material should be structured and organised must balance the demands and needs of both writer and reader.Report and essay writing requires a clear and sustained focus of information that directly supports the central topic or argument.In many cases, however, the research project will yield much more information.A written text must also function independently of its appendix.The central topic must be addressed within the main body of the text and all supporting arguments must not depend on material located in the appendix.In the case of sources that are richly referred to within the main text, it might also be useful to add the complete source paper or document in the appendix for the reader's convenience.An appendix may be one or many (appendices, in this case).The problem with this bulk of material is where to include it.If it is only loosely related to the topic, adding it to the main text might distract from the central argument and result in an unfocused piece of writing that is structurally messy and cluttered.