Fiducia TogetherSearching and sorting
Standard algorithms for finding an item and putting a list in order.
Please note: This page explains a word or a process in education. It is general information about the system, the law and the guidance in England — not advice about your child, your school or your exam. If a decision is going against you, get advice from one of the free services we link to before you agree to anything or miss a deadline. If you are revising, check your own exam board's specification: boards word things differently and yours is the one that marks you.
What it is
Linear search checks each item in turn. Binary search repeatedly halves a SORTED list. Bubble sort repeatedly swaps adjacent out-of-order items; merge sort splits, sorts and merges; insertion sort builds a sorted section one item at a time.
Where it applies
GCSE and A Level computer science.
How it works
These are taught because they illustrate efficiency. Linear search works on any list and is slow on large ones; binary search is far faster and requires sorting first.
Bubble sort is simple and inefficient; merge sort is more complex and scales far better.
How to use it in your work
State the precondition for binary search — the list must be sorted — every time.
When asked to compare, compare on a stated basis: number of comparisons, whether the list must be sorted, ease of implementation.
Be able to hand-trace one pass of bubble sort. It is a very common question.
Where to get help
Your teacher and your board's specification — the pseudocode and the required language differ between boards. Bitesize covers the concepts; the computer science song runs the topics.
Revise this with a song
These are ours. We write revision songs because a lot of people remember a tune when they cannot remember a page, and because revising out loud in the kitchen beats staring at a highlighter.
- The Computer Science Song The GCSE computer science topics, set to music.
Where to read more
Last reviewed 2026-08-28 by Fiducia Together · Next review due 2027-08-28
Please note: This page explains a word or a process in education. It is general information about the system, the law and the guidance in England — not advice about your child, your school or your exam. If a decision is going against you, get advice from one of the free services we link to before you agree to anything or miss a deadline. If you are revising, check your own exam board's specification: boards word things differently and yours is the one that marks you.