Finding Inputs, Processes and Outputs

Every problem can be split into three roles: the inputs are the data the program is given or asks for, the processes are the actions it performs on that data, and the outputs are what it must produce.

Imagine a school reading challenge. A program asks for a pupil's name and the number of books they have read. If the number is 10 or more, it shows a Gold award message; otherwise it shows a Keep going message.

To find each part, pick out every item of data the program is handed or asks for; those are inputs. Look for the work done on the data — a comparison, a total, a decision — and those are processes. Outputs are the things that must be displayed, printed, saved or used to control a device. Describe each one specifically: a label such as "the count" could mean anything, so write "the number of books read"; "the message" is vague, so name the award message.

If the challenge is changed so results are grouped by tutor group, the extra raw data you need is each pupil's tutor group. A group total is worked out from the book counts, so it is not an additional input. Only new data supplied from outside the program counts.