I’m about half way through my current WIP. I’ve got to the point where I’ve exhausted much of the research I did way back before I started, or what I researched then is no longer relevant to this part of the story. I suddenly find myself in the position of wondering, is this bit right? Or I discover when I check something that it’s not as easy to find out as I had thought. Or I start digging and end up getting sidetracked with the result that I have nothing much of any relevance to show for an entire day’s work except for a couple of sentences.
I can either allow myself to get sidetracked, because after all you can discover the most amazing things that might turn out to be relevant in the end, or I can be firm and put it aside and carry on with the story.
There is, of course, the theory that you should’t do any research at all until you have finished, so you will then avoid researching irrelevant material, but I don’t think I could do that; the plot could depend on something that was totally wrong.