Is the case study in Paper 1 or Paper 3?

From May 2027 the case study is Section B of Paper 1, for SL and HL. There is no Paper 3 any more.

Is machine learning on Paper 1?

Yes. Machine learning is topic A4, part of Theme A. The fundamentals and ethics are for everyone; data preprocessing and the approaches are reported as HL only.

IB Computer Science Paper 1: what it tests and how to revise

From May 2027, IB Computer Science Paper 1 examines Theme A: computer hardware and data, networks, databases and machine learning. Section B is about the pre-released case study, and both SL and HL answer it. It is reported as 1 h 15 min at SL and 2 h at HL. Revise it topic by topic, then practise full papers under time.

What is on Paper 1

A1 Computer fundamentals: the CPU and memory, binary and logic gates, operating systems and (HL) translation.
A2 Networks: network types and devices, topologies, addresses and packets, and network security.
A3 Databases: relational design, normalisation and SQL, plus (HL) alternative databases and data warehouses.
A4 Machine learning: the fundamentals and the ethics for everyone; data preprocessing and the approaches (regression, clustering, neural networks and more) at HL.
Section B: the case study. The IB releases it ahead of the exam, and questions apply Theme A ideas to it.

Paper 1 does not ask for full programs, which are Paper 2's job. It can still ask short technical answers such as an SQL query, a truth table or a calculation.

Start with A1.1 Computer hardware
Every Theme A topic has its own page with notes and questions.
All topics on one page
Which parts are HL only, and what is on this site for each.

How to revise for Paper 1

Go topic by topic. Check you can do each point on the topic page before moving on.
Learn the command words. "State" wants a fact, "explain" wants a reason, and "evaluate" wants both sides and a judgement.
Practise the calculations and diagrams: binary and hexadecimal, file sizes, truth tables, entity relationship diagrams and SQL.
Read the case study early, more than once, and practise applying Theme A ideas to it.
Do a full practice paper under time, then mark it with the mark scheme.

The 2027 case study guide
Generative AI for image creation, topic by topic.
Free Paper 1 practice papers
Timed SL and HL sets with mark schemes.

Questions students ask

Is the case study in Paper 1 or Paper 3?: From May 2027 the case study is Section B of Paper 1, for SL and HL. There is no Paper 3 any more.
Is there coding in IB Computer Science Paper 1?: Not full programs: writing code is tested in Paper 2. Paper 1 can still ask short technical answers, such as an SQL query or a Boolean expression, because those are Theme A topics.
Is machine learning on Paper 1?: Yes. Machine learning is topic A4, part of Theme A. The fundamentals and ethics are for everyone; data preprocessing and the approaches are reported as HL only.