As with every piece of substantial research, it can be a problem to decide what needs to stay in the main text and what can be left out without substantially impacting upon the ability to understand the narrative. This is where appendices can be useful, and an important role of the supervisor is to give gentle guidance on what needs to go into an appendix and what simply best kept in an archive. The temptation of the early career researcher is to believe that everything is necessary, and in the classic “can’t see the wood for the trees” mentality, to cram loads and loads of supplementary data into appendices that are rarely (if ever) read subsequently. The golden rule of an appendix is that it should contain information that is not so important that it needs to be in the main text, but that it can still substantially contribute to understanding the background detail of that main text by providing supplementary evidence. A good example of this would be a large table of numerical results (in a quantitative study) or a key interview transcript (in a qualitative study). Both of these types of appendix can furnish crucial raw data that can enable an experienced reader to ‘get behind’ that research results and help them to make their own interpretations of the results. (Or understand the decisions made by the research student).
An appendix is not an excuse to dump all the information that has been collected in the research but has not been able to find a place in the main text. Crucially, the appendices (and footnotes/endnotes) are included in the word count for a dissertation submission, so weighty appendices risk robbing space for the more substantial (and important) presentation of the main text arguments. If a point is critical to the development of the research conclusions or interpretations, then it should probably be in the main text; if it is important but not crucial to see in detail and can be summarised in the main text, then perhaps a fuller account can be included in an appendix. There will also be some information that has a background relevance but should neither be included in the main text nor the appendices, but this does not necessarily mean that it can be thrown away. There will be information such as lists of consultees, or anonymised participants codings, or transcripts of (most) interviews that might be needed in the months following completion of the research but reading these are not germane to understanding the narrative of the main text.
In some cases, for example if the researcher does not intend to continue with the research topic, some of this background research might be archived with the university library, or with the research supervisor. Increasingly, it is common for research that has received public funding to require that the raw data is made publicly available, and this creates new opportunities and new difficulties. If the data is required to be publicly accessible for ten years (or ten years from the last time the data was accessed) then it is conceivable that the raw data will be openly available for far longer than any individual research project, and possibly even longer than the lives of individual researchers. This places an important new responsibility on the researcher to be very organised and very transparent in their collection and use of data. It also requires an accentuated awareness by the supervisor (and then the student) about the inclusion of what information is relevant for the successful completion of the dissertation, what can go into an appendix, and what should be kept in an archive.