The Extended Essay in Computer Science
Everything needed to write a computer science extended essay: what makes a topic survive an examiner, an interactive builder for research questions, the four worked examples the IB has approved, and criteria A to E paired with what the May 2024 subject report says actually goes wrong.
- 4,000 words
- 30 marks
- 40 hours
- First assessment 2027
Free to use. Students join their class with a code from their teacher; teachers can create classes and track progress.
What is inside
- Choosing a topicWhich topics belong to digital society or economics instead, and how to narrow a question that is too broad to answer.
- Research question builderAssemble a question from a field, two methods, a metric and a controlled variable, scored live against four quality tests.
- Approved examples4 IB worked topics — support vector machine kernels, Huffman against arithmetic coding, RSA against elliptic curve cryptography, and A* against Dijkstra's algorithm.
- Criteria A to EAll 5 criteria with their strands and marks, each paired with the failings examiners reported, and a self-check you tick off.
- Sources, code and AIWhich sources can carry an analysis, where code belongs, and exactly where AI tools are and are not allowed.
- A ten-month schedule32 milestones from picking a territory to the viva voce, dated around the key dates your school sets.
Preview
The internal assessment is not a rehearsal for the extended essay
The single most expensive misunderstanding in computer science extended essays. The IA builds a product; the essay answers a question — and you may not reuse IA data or outputs.
| Internal assessment | Extended essay | |
|---|---|---|
| What you produce | A working software product for a named client. | An academic research paper answering a question. |
| What the code is for | The code *is* the assessed work. | The code serves the question — and lives in an appendix. |
| What gets marked | The product, the development, the evaluation. | The argument, the evidence and the reasoning. |
| Success looks like | The client can use it and it meets the criteria. | The question is answered, with limits acknowledged. |
| Sharing between them | Your IA data and outputs stay in the IA. | You may not reuse IA data or outputs. At all. |