AQA 7517 4.4.1.2: Following and writing algorithms
The free BugBot lessons that teach this point, a robot to try it on, and the past-paper questions that test it.
What it covers
Good programmers solve a lot of a problem before writing a line. Thinking ahead is working out, in advance, what a solution will need: its inputs and outputs, the conditions it relies on, what can be stored and reused. Thinking logically is working out where the decisions are and exactly what conditions control them. Both are how you write an algorithm that works first time, and how you argue that it does.
- Inputs, outputs and preconditions
- Caching
- Reusable components
- Thinking logically
- Following and writing algorithms
Or do it in the simulator, with tasks that mark themselves
Lessons that teach it
- A2.7 Thinking ahead and thinking logically Recursion and computational thinking
Inputs, outputs and preconditions, caching and reuse, decisions and conditions, and solving logic problems. - A15.1 How your A level is assessed Exam preparation
The papers and the project for OCR H446, AQA 7517 and Eduqas A500QS, the assessment objectives, and a timing plan built with integer… - A15.2 Command words and levels of response Exam preparation
What each command word asks for, how extended answers are marked in levels, and a marker that levels answers with regular expressions. - A15.3 Trace tables and hand-tracing Exam preparation
Tracing loops, recursion and Little Man Computer programs without slips, and a binary search that prints its own trace table. - A15.4 Pseudocode in the exam languages Exam preparation
OCR's exam reference language and AQA's pseudo-code side by side with Python, the traps in translating, and a stack class that brings the… - A15.5 Writing algorithms and code in the exam Exam preparation
Planning before writing, how code is marked, the standard algorithms to know by heart, and Dijkstra's algorithm driving the robot. - A15.6 Pre-release material and skeleton programs Exam preparation
Getting to know a skeleton program before the exam, the questions asked about it, and making exam-style changes to one. - A15.7 Calculation and theory questions Exam preparation
Number representation, floating point, Boolean logic, state machines and complexity answered quickly and checked. - A15.8 A revision plan and mixed practice Exam preparation
Mapping the specification, retrieval, spacing and interleaving, and a spaced repetition scheduler for the whole course.
Try it on a robot
The task from A2.7 Thinking ahead and thinking logically, running here. Change the program and press Run.
The specification is AQA's own document; this page says which of our lessons teach point 4.4.1.2 and is not endorsed by the board.