I have researched human evolution and created my own chart. I have written out a family tree that could span about 300-400 years back, with a short idea of the people on it. I spent time looking up common names in different regions to give my characters the correct surname. I've read more about blood than I can even remember.
Notebooks full of information and ideas that I've thought up. But how many chapters I have I written? well not notebooks, but not nothing. If only it were easier to write chapters than ideas.
but hers my reasoning - You have to know the history, the theory, the background of your world and characters before you can write them. How can you write the dialog of a person or describe how they walk or react to something when you don't know where they come from. How can you describe objects or things your characters interact with if you don't know what it is, how its created, or why its important in your world?
Are these valid reasons or just excuses? *sigh* One only knows how much research one needs until after she reaches the point of not needing any more.