AQA Computer Science GCSE
Algorithms show exactly how a task can be completed. Technically they are a sequence of step by step, unambiguous instructions for solving a particular problem.
You need to be able to read (and understand) algorithms written in pseudo-code and to be able to write algorithm answers using:
Most answers in the new syllabus seem to prefer answers written in Python and that's likely to be what you see in an exam. If you do get a question that asks for another method, you'll probably be given the choice of pseudo-code or a flowchart, and may well be given most of the pseudo-code you'll need anyway.
In an exam you may have to write an algorithm using any of three methods. There's no need to be able to write perfect pseudo-code. The key is getting the logic right, not necessarily writing with perfect syntax. But it is important to know what pseudo-code commands mean.
Key Definitions and Ideas
The key definitions here are really important. Look at the syllabus document. If a word is included in there you must be able to define it.
Algorithm basics - key definitions and ideas
Basic flowchart symbols - you might see a flowchart in an exam or need to produce one, so you need to make sure you know what each symbol means
There are some key programming ideas that you can use algorithms to help develop.
Algorithm Programming Constructs - an important set of key programming concepts and constructs and how they are developed in algorithms. You should have implemented all of these ideas using Python, but it's important to understand that they are key ideas in programming and know how they can be applied in non-program code algorithms. (Note: some of the pseudocode in this document is not AQA pseudocode - I might get round to updating it at some point, but the ideas are the important thing)
The Bitesize pages on algorithms and control flow are also useful - especially when you need to review sequence, selection and repetition. There are videos which might be helpful.
Exam style questions
Decomposition question - exam style question
Advantages and Disadvantages of using Decomposition - use this to help answer the last question (the 6 mark one)
Decomposition answers - answers to the questions