The content of a thesis or dissertation varies widely depending on the faculty member who serves as your advisor. Remember, it is primarily your advisor who will decide whether or not your ``writing" is acceptable as a thesis or dissertation.
Within the college of engineering itself, there are variety of thoughts and practices on this matter. One of the opinions is that each chapter (with the exception of introduction and conclusion) of your thesis/dissertation should be a publication in a refereed journal. Other advisors think that the thesis/dissertation should be a unified and coherent presentation of your research.
Your best bet is to talk to your advisor and look at a thesis or dissertation of someone who has graduated from your research group in the recent past to get a rough idea of what is expected.
Although what goes into a thesis or dissertation and in what order is a matter of taste (yours and your advisors), the Graduate School enforces a certain level of consistency among all theses and dissertations at Cornell. Before starting to write or compile your thesis, it is definitely a good idea to read the Graduate School's guidelines for theses and dissertations. These are available in booklet form from Caldwell Hall (DE4) or on the web at CLICK HERE.
Checking the guidelines ahead of time will help you avoid any major formatting changes later. Talk to your advisors and peers about how to be more efficient in this process.
In addition to the published guidelines, a member of the staff of the graduate school is responsible for checking and approving the format of all theses and dissertations submitted at Cornell. This person must approve the format of your thesis before you submit it, but the thesis advisor also has regularly scheduled office hours to help you ensure that you are meeting the thesis/dissertation guidelines as you prepare your thesis. It is especially important to see the thesis advisor if you would like to include special graphs, data, or other visuals that do not easily conform to the usual guidelines.