The assessment rule summarized above is based on the IB: Computer science curriculum updates ↗. Check the official version for your assessment session.
Current paper map: SL versus HL
According to the official 2027 curriculum update, the weighting differs by level. The old option paper and the previous HL-only Paper 3 are not components to prepare for under this syllabus.
| Component | SL | HL | Practice focus |
|---|---|---|---|
| Paper 1 | 1 h 15 m / 35% | 2 h / 40% | Concepts of computing systems and the case study are now assessed here, including case-study questions for SL. |
| Paper 2 | 1 h 15 m / 35% | 2 h / 40% | Computational thinking, algorithms and programming questions. Students can answer using Java or Python. |
| Computational solution (IA) | 35 h / 30% | 35 h / 20% | Solve a real problem using computational thinking and programming; show and evaluate your work. |
Worked exercise: separate case-study reasoning from programming
Teaching scenario: A school wants to use a program that prioritizes library requests. This is an invented case for practice, not an official IB case study.
Paper 1: system trade-off
Compare fairness, input data quality, privacy, system boundaries and who can challenge a decision.
Claim: 'automation is more fair' is not enough. Identify whom an edge case disadvantages.
Paper 2: algorithm choice
Define an input record, ordering rule, ties, missing fields, output and a test set.
Try two requests with identical priority and prove that the tie-breaking rule is deterministic.
IA: actual user problem
Establish a client's specific need, design a working solution and show testing against the need.
Avoid inventing a client, evidence or a completed evaluation; preserve genuine testing records.
requests = [(2, "A"), (1, "B"), (2, "C")] # First sort by lower numeric priority, then request ID ordered = sorted(requests, key=lambda r: (r[0], r[1])) # Result: [(1, "B"), (2, "A"), (2, "C")]
The sample demonstrates one ordering rule, not the new IB prescribed programming language or an endorsed priority policy. Real student solutions need tests for invalid data and legitimate constraints.
Avoid mixing syllabuses
Label every past-paper question with its assessment session before revision. For May 2027 onward, replace old HL Paper 3 preparation with current case-study questions within Paper 1, and practise programming on Paper 2. Your school should confirm the exact first-assessment course and official specimens you use.
Sources and verification
Primary-source references for this article, checked 12 October 2026. Rules and admission policies can change; confirm the current version for your assessment session or university course.
- IB: Computer science curriculum updates ↗
Official assessment model for first assessment May 2027, including removed Paper 3, case study, Paper 2 programming and IA.
- IB: Computer science course overview ↗
Course and teaching context.
Independent student guidance, not an official IB publication. Ask your school coordinator to confirm policies relevant to your circumstances.