How to Revise for IB Computer Science

Are your IB Computer Science exams approaching faster than expected? Perhaps your teacher has already asked whether you have started revising, or maybe you have just realised that getting the best possible grade will take more than a last-minute cram.

IB Computer Science is a demanding course. It requires more than surface-level knowledge, it asks you to think computationally, understand complex concepts, and apply them through programming and internal assessment. Unlike GCSE or other national qualifications, the IB focuses heavily on conceptual understanding and real-world application, which means your revision needs to be smart, consistent, and purposeful.

In this article, I will guide you through how to revise IB Computer Science effectively, using strategies that I have seen work time and time again with my students. These techniques are tailored to the structure of the IB curriculum and will help you prepare for Paper 1, Paper 2, and your internal assessment. 

You do not need to try everything at once. Instead, explore the approaches, reflect on what suits your learning style, and build a routine that works for you.

By the time you finish reading, you will have a clear, teacher-approved plan for revising IB Computer Science that strengthens your understanding, builds your confidence, and sets you up for success.

Revision tactics covered:

• Using past papers effectively

• Active recall with flashcards

• Mapping complex topics with mind maps

• Practising advanced pseudocode and algorithms

• Breaking down mark schemes

• Teaching someone else

• Managing time effectively during the exam

• Understanding command words in exam questions

Using past papers effectively

Past papers are one of the most effective ways to revise for IB Computer Science. They help you familiarise yourself with the command terms used in Paper 1 and Paper 2, as well as the structure and style of the case study questions.

• Start with untimed practice using your notes for support.

• Move on to timed practice to simulate real exam conditions.

• Mark your answers using the mark schemes and identify areas where you lose marks.

• Pay particular attention to your programming questions, especially in Paper 2 if you are taking the HL route.

One useful activity is to analyse several years’ worth of exam papers and categorise questions by theme (e.g. databases, networks, computational thinking). This helps you spot patterns and focus your revision on topics that are commonly assessed.

IB Computer Science is well known for putting a large focus on ethical and global awareness in Paper 1 for example, so that would always make a great place to start.

Active recall with flashcards

Active recall is a proven strategy to improve memory retention and reinforce key knowledge, perfect for mastering the theory-heavy Theme A topics.

• Create flashcards for key terms in topics like Boolean logic, data representation, machine learning and networking.

• Focus not just on memorising terms, but being able to explain and apply them.

• For HL students, include flashcards that test your understanding of abstract data types and OOP terminology.

Make sure to practise writing out answers to theoretical questions in full sentences to mirror exam conditions.

Flashcards were a key part of my classroom practice. All students created flashcards on important topics as we worked through the syllabus. You can use either digital or paper-based flashcards, depending on what suits you best. They are especially useful during revision lessons, and they work brilliantly alongside exam question practice and past paper sessions.

Mapping complex topics with mind maps

The IB syllabus encourages you to make conceptual links between different topics. Mind maps are a great way to visualise how different themes and subtopics connect.

• Start with a high-level concept like "computational thinking" or "machine learning".

• Branch out into subtopics and link to example questions or scenarios.

• Use colour, icons, and keywords to make it memorable.

• Include real-world applications and ethical considerations to boost your Paper 1 response.

This is especially helpful when revising for the case study or the internal assessment, where showing understanding across multiple areas is essential.

Students who created their own mind maps and personalised them with colour, drawings, or code examples often found them more helpful, as they felt a stronger connection to the material. 

It is best to avoid using mind maps made by other people. Your notes should be written in your own words and explain ideas in a way that makes sense to you. When you rely on someone else's work, it becomes much easier to misunderstand key concepts and form misconceptions.

Practising advanced pseudocode and algorithms

IB Computer Science expects you to write and understand pseudocode and translate between pseudocode and real code (in Python or Java).

• Practise implementing common algorithms (e.g. searching, sorting, pathfinding).

• Write your own pseudocode and then test it in your chosen language.

• Focus on recursion, data structures (stacks, queues, trees, graphs), and the logic behind each solution.

• Use past Paper 2 questions to practise applying these in an exam context.

HL students should also review more advanced content like abstract data types and problem decomposition using OOP principles.

I once taught a student who really struggled with the programming side of IB Computer Science. They understood the theory but often froze when faced with a coding question. We talked about building confidence through practice, and they committed to completing one small coding challenge every day after school. These were not huge tasks, just 10 to 15 minutes of focused practice using past paper questions and short programming problems.

Over time, their confidence grew. By the time the exams came around, they were not only completing the programming questions with ease, but they had also started helping others in class. That daily habit made all the difference. It showed me, and them, that consistent effort beats cramming every time.

Teaching someone else

Teaching a topic is a powerful way to consolidate your understanding. The IB encourages communication and collaboration, so make use of this in your revision.

• Explain difficult topics to a friend or family member.

• Create short videos or visual explainers and share them with your study group.

• Use the Feynman Technique to simplify complex ideas into language a younger student could understand.

This works especially well for internal assessment preparation, where you need to explain your solution clearly and evaluate its success.

One of my students decided to explain recursion to their younger sibling, who had no background in Computer Science at all. They used simple diagrams, everyday examples, and even built a paper model to show how the call stack worked. At first, they struggled to break it down clearly, but by the end of the session, not only had their sibling grasped the basic idea, but the student also felt far more confident tackling recursion in class and in their internal assessment. Teaching forced them to confront the gaps in their own understanding and fix them.

Managing time effectively during the exam

Good time management can have a huge impact on your final grade.

• In Paper 1 and Paper 2, allocate time-based on mark value.

• Use the ‘Two-Pass Rule’: tackle the easiest questions first to secure marks, then return to harder ones.

• Practise full-length papers to improve your pacing.

Some students like to start with the case study section in Paper 1 to gain confidence, try different approaches and find what works for you.

One of my past students realised that they kept running out of time in Paper 2, often leaving the last question unfinished. We worked together on timing strategies, including practising with a stopwatch, setting mini-deadlines for each section, and using the reading time more effectively. 

After a few weeks of timed practice, they were finishing every paper and saw a noticeable jump in their marks. Simply learning to manage their time better gave them the chance to show what they really knew.

Understanding command words in exam questions

The IB uses specific command terms like "describe", "explain", "compare", and "evaluate", each with a precise expectation.

• Review the official list of command terms and practise matching answers to what the question is really asking.

• Use writing frames or templates to help structure responses.

• Identify the command term before writing any answer.

This is key for Papers 1 and 2 where clarity and precision often separate top-mark answers from mid-level ones.

Breaking down mark schemes

Learning how marks are awarded gives you insight into how to write effective answers.

• Review mark schemes alongside past papers.

• Identify common wording and formatting that earns marks.

• Try peer marking with friends using the mark scheme.

Also, study examiner reports if available, they reveal common mistakes and give feedback that can fine-tune your technique.

Students found that reading examiner reports helped them spot patterns in the types of mistakes students often make. They started reviewing their own practice answers alongside the examiner’s comments and began to recognise where their explanations were too vague or where they had missed key command words. By actively using this feedback, their answers became sharper and more focused, and their grades improved steadily.

Final thoughts

Revising for IB Computer Science means more than just memorising terms, it’s about applying concepts, solving problems creatively, and communicating your thinking clearly. Use these tactics to strengthen your revision routine and approach your exams with confidence.

Try them out, adapt them to your learning style, and most importantly, stay consistent.

Good luck with your revision!

References
International Baccalaureate Organisation