1) I am the participant-observer in my own life.
Participant-observers study a society while participating in it. Obviously, writers study more than a society, but I, and many writers that I know, tend to experience things in two layers. The first is "I'm experiencing this." The second is "And how will I write this when I need to use it in a book?" The first layer is not always the first layer experienced, either.
2) Every novel is an interior ethnography.
I'm not talking about an ethnography of that alien race that the book seems to be about. I'm talking about the ethnography of one's own psyche, and the multitudes therein. Even the book that is the ethnography (yes, am most assuredly abusing this term) of one's own family is just as much about the interior life of the writer as it is about the family. You can't remove the family from the interior life, anyway, not really.
While I do not believe that a book necessarily reveals anything concrete about the author--one should never assume that a political opinion expressed by a character also belongs to the author, or that an author who writes about X has actually experienced X--every book reveals something about the author.
If you choose to spend six months to three years immersed in a world, a culture, a life, an experience not your own, it says something about you, and the choice of what you choose to be immersed in says something about you. Ninety-five percent of people might draw the wrong conclusion about what it says about you, and there's no code to figuring out everyone's interior ethnography, but still, it's there. And you, the author, know it. You are your own ethnographer.
Hm. I think there's more, but I must mull. And write.