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Computer Science IA Criteria Guide

Connect the problem, algorithms, product and tests.

For assessment in 2027. Document the computing problem, planning, system design, development and evaluation. Include a video of the product working and the full source code as required by the IB.

Assessment criteria

What each criterion measures, how many marks it carries, and what stronger evidence usually looks like.

Criterion names, marks and mark bands follow the IB subject guide. The band descriptions are our own summaries, so check your subject guide for the exact wording.

Criterion A: Problem specification (4 marks)

Define the problem, measurable requirements and the computing approach.

Stronger evidence
The problem has measurable requirements, suitable targets and a reasoned choice of computing approach.
Early-stage evidence
The problem and computing approach are sketched out, with few measurable targets.

Criterion B: Planning (4 marks)

Break the problem into manageable parts and plan how to meet the targets.

Stronger evidence
The breakdown makes the problem manageable, and the plan covers the stated targets.
Early-stage evidence
The breakdown is incomplete and the plan covers only part of what the product must do.

Criterion C: System overview (6 marks)

Show the system's parts, algorithms and planned tests.

Stronger evidence
The system design is complete, its algorithms would work, and the test plan addresses the stated targets.
Early-stage evidence
The system is only sketched out, algorithms are named, and testing covers at least one target.

Criterion D: Development (12 marks)

Explain how the working product was built and how testing supports it.

Stronger evidence
The product works fully. Suitable techniques implement the algorithms, choices are critically weighed and testing effectiveness is justified.
Early-stage evidence
The product barely works. Coding techniques are unsuitable, and choices and tests are only listed.

Criterion E: Evaluation (4 marks)

Judge the finished product against its targets and justify improvements.

Stronger evidence
The report judges how well the targets were met and gives reasons for proposed changes.
Early-stage evidence
The report says which targets were met and describes possible changes.

Mark bands

Want to know where your IA sits in these bands? Upload your draft and get a mark for each criterion.

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How to build it

Most weak drafts fail on order, not on ideas.

  1. 1

    Specify the problem

    Explain the problem, measurable requirements and success criteria. Give reasons for the computing approach you choose.

  2. 2

    Plan and design the system

    Break the problem into smaller parts. Show the system components and algorithms, and plan tests against the success criteria.

  3. 3

    Explain development decisions

    Use relevant code examples to explain your techniques and choices. Describe how testing informed development.

  4. 4

    Demonstrate and evaluate the product

    Use a video of up to five minutes to demonstrate functionality and example tests. Evaluate the success criteria, justify improvements and include the full code in an appendix.

Before you submit

  • The success criteria can be tested.
  • The system overview includes components, algorithms and a test plan.
  • Code examples explain the important development choices.
  • The video demonstrates functionality and testing; the full code is supplied.

Quick wins

  • Trace each planned test to a success criterion.
  • Explain why a technique fits your algorithm.
  • Use the evaluation to justify changes rather than list wishes.

Check your Computer Science documentation

Get marks and comments on your PDF documentation against the IB criteria. Video functionality still needs review. The result includes a mark for every criterion, evidence from your draft, and the changes to make first.

Grade my IA draftSee pricing
  1. 1

    Upload your IA draft as a PDF

  2. 2

    Get a mark and feedback for every IA criterion

  3. 3

    Revise and grade the new version

A mark for every criterion
A mark for every criterionSee where the draft is now, criterion by criterion.
Comments on your sentences
Comments on your sentencesEach comment points at the passage it is about.
What to fix first
What to fix firstConcrete next edits instead of "improve your analysis".