Now, for this next activity, we need some equipment. If you look under your tables, you’ll find that I’ve left each of you an invisible bag. Have a look now… An invisible bag, there should be one under every desk? That’s it, Michael! Hold it up so everyone can see. You should all have an invisible bag, just like Michael’s. Don’t look in them just yet… Right. Inside your bag are six invisible thinking hats. We’re going to do an activity that requires you to wear each hat in turn, each hat will make you think in a different way, and when you have finished with each hat, you’re going to put it back in the bag. Understood? Ok. Everyone open up your bag, and find the white hat…. put it on. Well, Sarah, that’s a very fetching shade on you! Jamie, excellent, well done. Ok… The white hat helps you to think about the facts of the problem. Look at your problem sheet and write down ONLY THE FACTS about the problem.
Now, then. We’ve finished with our white hats, put them back in the bag. Jamie! I saw that, pick it up! Throwing your invisible white hat on the floor – shocking behaviour – pick it up…. that’s it… now put it in the bag. Michael – Sarah – it’s lovely that you’ve got your red hats on already, but let’s just wait for the rest of the class… Phillip! Stop fighting over that invisible bag! Don’t make me have to explain to your Mum why you’re in an invisible detention!
So, red hats…
(some time passes by… every time there is a hat change, a significant amount of the students simply throw their invisible hats on the floor, some throw them out of windows, some seem to simply imagine that once they have finished with a hat it vanishes, and they don’t have to clear it up… they think I haven’t noticed, but I have)
Right, you lot. It’s time to pack away, it’s nearly breaktime. But none of you will be going anywhere until this mess is cleared up. Seriously! Look at all these invisible hats strewn around the place! Who do you imagine is going to clear this all up?
A small voice, comes from the back of the class: “Miss? Miss? I have a giant invisible hoover. I can do it!”
And, indeed, he did just that.

(true story)