Partial-closed world assumption

Well kiddo, when we talk about the "world" in this case, we mean a big set of things that we can know about. Sometimes we don't know everything about the world though, so we have to make assumptions about what we don't know.

When we make a "closed world assumption," we assume that if we don't know something, it doesn't exist. Kind of like if you don't see your crayons on the table, you assume they don't exist and must be somewhere else. But as you get older, you realize that sometimes things could be hidden or out of sight, so you can't always assume that they don't exist.

That's where the "partial-closed world assumption" comes in - instead of assuming that something doesn't exist if we don't know about it, we assume that we just don't know about it yet. It's like if you're playing hide-and-seek and your friend is hiding somewhere you haven't searched yet - you don't assume they're not there, you just keep searching until you find them.

So basically, the partial-closed world assumption is a more flexible way of thinking that allows us to consider that there may be things we don't know about yet, instead of assuming they don't exist just because we haven't seen them.