I've received some questions from a reader of this blog about starting a dissertation or first book project. Her first questions are
"How do you know how much research is enough? When do you start writing?"
I'd say, the take that second question first, that you should begin writing immediately. Write an essay just for yourself about what you know about your topic. You will never really have a blank page facing you, because you will have already have written something. You can try an encerrona, for example. Lock yourself in a room for 5 hours and write something. This should be done once you have a topic, and before you have done extensive research.
The real question here, though, is when you should end the research phase of your project and begin the writing phase: how much research is enough before you know it's time to start writing? Here, I would say that you will have been writing up your research notes all along. You will know when an argument emerges out of those notes that demands to be chapter. Once you start writing that up, you will know if you have to do additional research and reading. Research needs to be guided by some firmly articulated questions. In other words, you have to know what you are looking for in very concrete terms. Obviously those questions are going to get more precise as you work.
There are students who want to put the entire contents of their research into their dissertations. The problem is not that they know too much about their topics, but that they haven't learned to distinguish between research that belongs in the finished project and information that should remain as background. Once you find yourself in the situation of knowing more than will actually "fit," then you should stop researching and begin writing. In the course of developing an argument, you may find that you haven't answered a question you need to answer--so more research is needed, but of a very directed variety.
Really, all the SMTs are valid for the dissertation as for any other project, but there are specific problems that writers get into because of the nature of the dissertation requirement and the lack of self-assurance inherent to writers at this stage. I'll be addressing some of these problems in subsequent posts.