ABSTRACT
Imagine you have some play dough in your hands. You are going to make something, a mouse, perhaps. What do you do? Firstly, you might squeeze and manipulate the piece of dough from a rough, stiff lump into something more malleable and smooth. You might roll it into a ball or a sausage shape, or break it into several pieces. You might start to shape your mouse body, and then craft the head. You might take some tiny balls of dough to create ears, eyes and a tail. You might pinch the head to create a sharp, pointy nose. You might puzzle about how to do whiskers. As you create your mouse, you will almost certainly pause to look at it and see how it is coming along; you might even decide that what you have done is not working and screw your creation back into a malleable ball of play dough, and start again.
