Cambridge O Level Computer Science · Syllabus 2210 · Algorithm Design and Problem-Solving
Inputs, Processes, Outputs and Storage
What is Inputs, Processes, Outputs and Storage?
Inputs, processes, outputs and storage — IPOS — is the four-way analysis of a problem, separating the data supplied to a system, the calculations and decisions performed on it, the results reported to the user, and the values kept for later use.
This definition is part of the Algorithm Design and Problem-Solving chapter in Cambridge O Level Computer Science.
Inputs, Processes, Outputs and Storage in context
Topic 7 is about the work that happens before and around writing code. You analyse a problem (identify it, strip away what does not matter, break it into parts, and name the inputs, processes, outputs and storage), you design a solution (structure diagram, flowchart, pseudocode), you code it, and you test it with data you chose on purpose. Along the way you use a small fixed set of standard methods — linear search, bubble sort, totalling, counting, maximum, minimum, average — you protect the input with validation and verification, and you prove behaviour with trace tables and with normal, abnormal, extreme and boundary test data. Nothing in this topic requires you to be fluent in a programming language; it requires you to be exact.