Representing Algorithms
Overview
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.
Objectives
- Understand and explain the term algorithm.
- Understand and explain the term decomposition.
- Understand and explain the term abstraction.
- Use a systematic approach to problem solving and algorithm creation representing those algorithms using pseudocode and flowcharts.
- Explain simple algorithms in terms of their inputs, processing and outputs.
- Determine the purpose of simple algorithms.
Mind map
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Lesson Note
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Lesson Evaluation
Congratulations on completing the lesson on Representing Algorithms. Now that youve explored the key concepts and ideas, its time to put your knowledge to the test. This section offers a variety of practice questions designed to reinforce your understanding and help you gauge your grasp of the material.
You will encounter a mix of question types, including multiple-choice questions, short answer questions, and essay questions. Each question is thoughtfully crafted to assess different aspects of your knowledge and critical thinking skills.
Use this evaluation section as an opportunity to reinforce your understanding of the topic and to identify any areas where you may need additional study. Don't be discouraged by any challenges you encounter; instead, view them as opportunities for growth and improvement.
- Which statement about algorithms and programs is correct? A. Every algorithm is a computer program B. An algorithm is a method, and a program is one implementation of it C. A program can implement only one algorithm D. Algorithms can only be written in pseudocode Answer: B
- A designer replaces a detailed street map with a simplified diagram that shows only which roads connect to which junctions. Which term describes what has been done? A. Abstraction B. Decomposition C. Iteration D. Validation Answer: A
- In the OxfordAQA pseudocode used in assessment material, which symbol means assignment? A. == B. = C. A left arrow D. := Answer: C
- Which flowchart shape is used for a decision? A. A diamond B. A parallelogram C. A rectangle D. A rounded box Answer: A
- An algorithm reads a list of numbers from a text file, finds their total, and writes the total to the screen. How many inputs and how many outputs does it have? A. 0 inputs and 1 output B. 1 input and 1 output C. 1 input and 0 outputs D. 2 inputs and 1 output Answer: B
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