A generic exercise I use when I teach design involves defining what a door is: what elements and functions make it a “door”? So we do that every college catalog ever features, with eager students calling out ideas and the dynamic teacher scribbling them on the board: Hinges! Knobs! Well, OK, handles! Windows! It’s genuinely interesting leading students from concrete (wall, hinge) to abstract (surface, rotational axis). As things progress, you can get to a point where everyone understands — some in everyday language, others more precisely — something like a door is an aperture with one or more stateful mechanisms that can determine whether or how creatures and/or things pass through it. But the fun comes when you draw a matrix of elements and functions (like the one here) and use that to invent new kinds of doors: revolving cat doors, sliding screen trap doors, dutch flap doors, etc. And — if the situation allows it — you can end up with surprising elements like doors of perception or rear-hinged “suicide doors” (see image) , and from there things like sliding screen doors of perception or suicide revolving doors.
This exercise is a pretty accessible way to show how to abstract things — so it lends itself to different levels of abstracti0n. You can present it as slapstick fun to elementary kids or as a lifehackish way to analyze things to undergrads. At the grad level it gets really interesting: younger grad students often enjoy a chance to loosen up and do undergrad-like things, and you can also add higher levels of abstraction to it. So, for some, you can point out that this approach is basically a technique for generating chindogu , for others, that it’s the first step toward building a Turing machine.
(Images: the first is doing the rounds, the second is from Wikipedia.)
