Nope. Instead, think of it as writing a piece. Not a chapter, not half of a chapter, but a piece. The first step is outlining the dissertation--figure out what the chapters will be. Yes, you can change the outline and will. Then outline the chapter you want to write--sections, sub-sections and even sub-sub-sections. Then try on any given day to write a sub-sub-section. That way, you have a reasonable goal which will either be finished or half-finished. As opposed to the daunting challenge of: oh, I am writing a book today.
If you know you have to write a specific piece, then you can do all the prep work aimed at writing that piece--doing the research, marshaling the notes and conceiving of the piece as a coherent section that has an explicit purpose. That way, when you write it, you know what you are trying to do. And once written, you will be able to answer the key question--does this piece fit into the larger project? Because there is the most fundamental challenge of dissertation/book writing: only putting in that which is relevant. If you know what the piece's purpose is, and that is what the organizing of the outline will define, then you will know whether it fits or not into the larger argument of the book.
I don't count words per day. I count pieces. Often, it is one piece per day, sometimes more than that, depending on the size of the piece, its complexity, my state of mind, how much time I have, and all that.
What do I mean by a piece? A few examples from my stuff (since it is what I know best):
- Ties That Divide had chapters on how many countries reacted to each particular secessionist crisis. So, a piece would be how country x reacted to the crisis--South Africa and Katanga or Germany and Yugoslavia. A second piece would be the politics of country x.
- NATO in Afghanistan had several case study chapters which followed the same pattern: what did the Dutch do in Afghanistan and what were the restrictions they faced would be one piece and the politics that explained such patterns would be the second piece.
- Not all pieces can be done in a single session, but they require far fewer sessions of writing than a book or a chapters
- Pieces are disposable! Just because you learned something does not mean it belongs in the dissertation, so you may end up writing something that is not useful for this project. However, don't delete it entirely--put it somewhere else on your harddrive because it might be useful for another project. See my Egg theory of writing.
- This only works if you have either a conscious or unconscious outline of the project.
- It can create a choppy draft as you have a bunch of pieces. You will need to revise to make it flow. I am still very choppy in my writing. I'd like to think I am clear and organized, but smooth? Maybe not.
- The aim of writing a dissertation or pieces is not to have a perfect document, but to have something that can be revised into something that is a decent draft of a book/article/dissertation. Which will be revised again and maybe circulated and then revised again. Easier to revise than write.
- There really are no rules so ignore this if it does not work for you.