IB Computer Science HL exam-day guide
IB Computer Science HL · Prepare for the day ahead.
Your checklist
Photo ID
Bring the identification document your school or test centre requires. Confirm with the provider which forms are accepted and whether a school-issued ID is sufficient.
Exam admission statement or candidate number
If your school issues an admission slip, candidate number, or session timetable, bring it. Confirm with the provider whether it must be printed or can be shown on a phone.
Two or more pens and pencils
Paper 1 and Paper 2 are written papers. Bring dark blue or black pens for written answers and pencils plus an eraser for any diagrams or tables. Confirm with the provider whether pencil-only sections exist.
Clear pencil case or pouch
Use a transparent case so invigilators can check contents quickly. Confirm with the provider whether non-transparent cases are removed at the desk.
Non-programmable calculator
You may need it for number conversions, storage calculations, or algorithm trace tables. Confirm with the provider which calculator models are permitted and whether programmable or graphing calculators are banned.
Wristwatch (non-smart)
A simple analogue or digital watch helps you pace the two papers. Smartwatches and phones are normally not allowed at the desk. Confirm with the provider whether any watch is permitted.
Printed formula and pseudocode reference (if allowed)
Some centres allow a clean copy of the IB pseudocode conventions or a formula sheet. Confirm with the provider whether any reference material is allowed and in what form.
Water in a clear bottle with labels removed
Stay hydrated during the longer paper. Confirm with the provider whether water is permitted at the desk and what bottle type is accepted.
Review the command terms
Know the difference between state, outline, describe, explain, compare, discuss, and evaluate so you allocate the right depth to each mark. This is the single highest-value revision item in the final days.
Confirm paper timings and venue
Check the start time, room, and duration for Paper 1 and Paper 2 with your school or test centre. Confirm with the provider whether the papers are in the same session or separate sessions.
Plan arrival with buffer time
Arrive well before the start time to allow ID checks and seating. Confirm with the provider how early candidates should arrive and what happens if you are late.
Leave prohibited devices behind or powered off
Phones, smartwatches, and any wearable technology should be switched off and stored away from your desk. Confirm with the provider the exact device policy and consequences for a device being found.
Plan the day
Shift from learning new content to active recall and exam technique. Re-read your own summaries of the four HL topics: system fundamentals, computer organisation, networks, and computational thinking. For each topic, write from memory the key definitions, diagrams, and processes, then check against your notes. Practise at least two full past-paper questions under timed conditions, focusing on the 6- to 8-mark extended responses. Mark your answers against the mark scheme and note where you lost marks: missing command-term depth, incomplete trace tables, or vague definitions. Do not start a new textbook chapter in this window.
Build a one-page 'traps' sheet: binary and hexadecimal conversions, two's complement, logic gate truth tables, cache and memory hierarchy, OSI and TCP/IP layer matching, subnetting basics, and the standard algorithm patterns (linear search, binary search, bubble sort, selection sort). For Paper 2, rehearse the structure of a longer response: define the problem, outline the algorithm or design, justify choices, and state assumptions. Sleep on a normal schedule; do not trade sleep for extra revision.
Do a light review only: your traps sheet, command terms, and the mark allocation pattern of the papers. Pack your bag with ID, admission documents, pens, pencils, eraser, clear pouch, calculator, watch, and water. Confirm the venue, start time, and transport plan. Eat a normal meal and go to bed at your usual time. Avoid cramming new material or discussing topics you have not revised; it raises anxiety without adding marks.
Eat a proper breakfast and arrive early. Do a 15- to 20-minute warm-up: read your traps sheet and one short mark scheme, then stop. In the exam room, before the start, check that your desk has the correct paper and that your calculator is in the permitted mode. Take a few slow breaths and set a pacing plan: for each paper, note the total marks, divide by the time, and identify the marks per minute so you know when to move on.
Read the whole paper quickly and mark questions you can answer confidently. Start with those to bank marks and build momentum. For each question, underline the command term and the number of marks, because marks signal how many distinct points are expected. For 'explain' and 'discuss' questions, write in full sentences with a clear point, mechanism, and consequence. For trace tables, use a ruler or straight edge and show every variable at every step; do not skip iterations.
For extended responses, plan for 30–60 seconds: list the points you will make, then write them in order. Use labelled diagrams where they earn marks, and define terms before using them. If a question stalls you, leave a gap, mark it, and return later. Keep an eye on time: aim to finish with 5–10 minutes to spare. In the final minutes, check that you have answered every question, that units and number bases are stated, and that you have not left a multi-part question half-finished. Cross out rough work clearly if it is not part of your answer.
Rules to check
Bring the identification document required by your school or test centre and present it when asked. Confirm with the provider which forms of ID are accepted and what to do if you do not have one.
Follow the invigilator's instructions at all times, including when to start writing, when to stop, and how to leave the room. If an instruction is unclear, raise your hand and ask before the paper begins.
Phones, smartwatches, and other wearable or connected devices must be switched off and stored away from your desk unless the provider explicitly permits otherwise. Confirm with the provider the exact device policy and the consequences of a device being found.
Do not communicate with other candidates during the exam, and do not share or request information about the paper during any supervised break. If the papers are in separate sessions, confirm with the provider what discussion is permitted between them.
Use only permitted equipment. Confirm with the provider whether calculators, reference sheets, or water bottles are allowed and in what form, and keep your desk clear of anything not approved.
If you need to leave the room for a break, raise your hand and wait for an invigilator. Confirm with the provider whether supervised breaks are allowed and whether extra time is granted.
Marks are awarded against the mark scheme, so answer the question asked: match the depth of your response to the command term and the mark allocation. Extra irrelevant material does not earn marks and can cost you time.
If you believe there is an error in the paper or a problem with your environment, report it to the invigilator immediately. Do not attempt to resolve it yourself. Confirm with the provider how such reports are handled.