While two common formats of dissertations have been the treatise format or a format containing a collection of stand-alone chapters under an umbrella theme, this does not have to be the case. Academic programs and dissertation committees are welcome to consider theses that are a collection of published essays or papers that contribute to more than one thematic area. For example, if a student has published essays or papers that individually make substantive contributions, then the dissertation committee may decide that the total contributions of these papers are sufficient for the dissertation even though they may not be collectively substantive in a single thematic topic area. This option may be very beneficial to a student who had to switch topics or advisors during their studies.