I enjoy stories that add some complexities, depending upon me, as the reader, to use some intelligence. One component of that is the use of limited knowledge with characters. Each character’s knowledge may overlap in part with that of other characters, but knowledge is unique to each character. This is common sense, but it isn’t something that I always make use of in my writing.
While in college, I took a couple of psychology classes, and one of the interesting topics discussed was child development. I recall a study with children where children were shown a scene (perhaps from a movie or picture book) and asked to comment afterwards. The scene was something like this: Sam plays with a toy, places it in a box and leaves the room. While Sam is out of the room, Sally takes the toy out of the box, plays with it and puts it in the closet. When Sam returns, he wants to get the toy. Where will Sam look for the toy? Young children (I don’t recall the average age) will answer that he will look in the closet, not realizing that Sam doesn’t know what they know.
Now, shift this back to writing. Sam and Sally are characters in a story. We can make use of the facts Sam knows to do some interesting things but only if we trust the reader to realize Sam’s limitations. In the past, I’ve sometimes avoided this so that I wouldn’t confuse the reader, but in retrospect, I think I didn’t trust the reader enough. The danger, of course, is adding too many characters with too many facts. If I need to keep notes while I’m reading a story just to keep myself straight, I’m not going to enjoy it. That might work for text adventure games, but not for short stories.
The device of limited character knowledge can add the right degree of complexity to a story, and I encourage its use for others as well as for myself.