Representing Algorithms

Somebody who has never seen your kitchen can still cook your grandmother's stew, because the recipe does not depend on who is holding the spoon. It lists what goes in, what to do in what order, and what you should have at the end. Change the cook and the stew is the same. That transferability is the whole point, and it is also the whole point of an algorithm: a set of steps precise enough that following them blindly still produces the right result.

This lesson gives you the three words the specification opens with, and they are the three that everything else in the course leans on. An algorithm is the method. Decomposition is breaking a problem that is too big to think about into pieces that are not. Abstraction is deliberately throwing away the detail that does not matter so that the part that does becomes visible. Then you will learn to write a method down twice over, once as pseudocode and once as a flowchart, using the exact conventions the examiners use, and to read somebody else's algorithm closely enough to say what it is for.