I've been wrestling with them for the last few days, and so far, I think it is a lot harder to rewrite something in MRUs than it is to write it from scratch. I'm still going to rewrite what I have already written, because I believe it will make my work much stronger. I am also a firm believer that if you learn something the had way, you'll learn it that much better.
Some scenes lend themselves to MRUs much better than others. The scenes, I am having difficulty with, are the ones where it is hard to identify the external motivation.
If you haven't read Randy Ingermanson's Writing the perfect scene Perfect Scene, or his series of blogs on MRUs then it is well worth checking out.
Let me allow Randy to explain how MRUs work.
The Motivation is external and objective, and you present it that way, in objective, external terms. You do this in a single paragraph. It does not need to be complicated.
The Reaction is internal and subjective, and you present it that way, exactly as your POV character would experience it -- from the inside. This is your chance to make your reader be your POV character. To repeat myself, this must happen in its own paragraph (or sequence of paragraphs). If you leave it in the same paragraph as the Motivation, then you risk whip-sawing the reader. Which no reader enjoys. The Reaction is more complex than the Motivation. The reason is that it is internal, and internal processes happen on different time-scales. When you see a tiger, in the first milliseconds, you only have time for one thing -- fear. Within a few tenths of a second, you have time to react on instinct, but that is all it will be -- instinct, reflex. But shortly after that first reflexive reaction, you will also have time to react rationally, to act, to think, to speak. You must present the full complex of your character's reactions in this order, from fastest time-scale to slowest. If you put them out of order, then things just don't feel right. You destroy the illusion of reality. And your reader won't keep reading because your writing is "not realistic." Even if you got all your facts right.
Now, the problems I've experienced are with internal motivation. Surely there is internal motivation - a thought for example?
Well, er, no, not that I've found anyway! So, this is where it gets tricky. Very tricky.
As a result, I've been struggling with some passages in my book.
But then, maybe I've been looking at it all wrong. Maybe I have to write it as a reaction, and just a reaction. Looking at Randy's series, it seems that way. The motivation may be obvious and therefore not written. For example, let's say my POV character presses a button. The presence of the button is the motivation, but maybe I don't have to write about the button until my character actually presses it. Otherwise we have a series of one line paragraphs, and frankly, they look pants.
Well I think I have it right anyway.