Getting groups of kids to come up with original ideas can be challenging. You don't want to just feed them things that they parrot back to you, but you don't want to feel like an idiot in front of a room full of blank stares and murmuring either.
Here is how to make sure that you get the ideas flowing early and often: Prompt.
Prompting is where you throw out ideas, not because you want the class to use them, but because you want them to open up their thinking.
For example: Suppose you are trying to come up with the main character for a story. It can be anything, but it has to be original.
So, you prompt the class, first with categories of things they could think about. For example, you could say, "This character could be a person, or an animal, or an object..."
Then, you rapidly throw out some examples that fall into those categories. For objects, you could prompt with "appliances," or "furniture," or "farm equipment..."
The students will then begin to throw out their own specific ideas. Very often, those ideas will be based on something from their own life. For example, whenever I work with kids in the mid-morning they seem to come up with lots of ideas that involve food because they are thinking about lunch...
Kids' brains are so lightning-fast, that all you need to is suggest some categories and the ideas will come spilling out. Just give them something to latch on to.
Beware, though: You don't want to throw out ideas that are too specific and make it like a multiple choice test. You just want to rev them up.
And, you don't want to just say, "So, what would be a good main character for our story? It could be anything..." This is where you get the blank stares. Nothing to latch onto.
It takes a little practice, but prompting is really powerful. It opens kids' minds to the possibilities, but lets them then take the lead.
So remember: Pose the problem, then start with broad categories, then offer some examples... and then let 'em run with it.