How Educerie is made.

Every note and question is original. We draft with AI, then check it against the syllabus, the published question bank and standard textbooks. AI makes questions cheap to write, but much of what it writes is subtly wrong, and a wrong answer key teaches a student the wrong thing. So most of the work here is the checking.

SourcesQuestionsNotesDiagramsMock papersMarkingThe study system

Built from the syllabus, never copied.

What we write from

  • ✓The IB subject guides
  • ✓The College Board's SAT framework and AP course descriptions
  • ✓Open textbooks and standard course books, read to check, never quoted
  • ✓Open data, with a credit line wherever it is used

Never used

  • ✕Other people's question banks
  • ✕Paid prep books
  • ✕Past-paper questions, reworded

Past papers and specimens are read only to match each paper's format and difficulty.

How a question is written.

Two different AI models do the work: one writes, and a second one, which never sees the writer's answer, works every question out again and fixes it. Scripts then check what neither model can be trusted to notice. A question goes live only when all three agree.

A finished question, taken apart

Economics · 1.1Easy

Which of the following is a leakage from the circular flow of income?

A
Spending by foreign buyers on the country's exportsThe mistake it catches: mixing up exports, an injection, with imports, a leakage.
B
Saving by households out of their incomeThe answer: income households receive but do not spend.
C
Wages paid by firms to the households that work for themThe mistake it catches: taking the flow itself for something leaving it.
D
Spending by firms on new machineryThe mistake it catches: investment is spending added to the flow, an injection.
  • ✓Tied to one point of the syllabus (here, 1.1)
  • ✓Every wrong option is a mistake students really make
  • ✓The explanation says why each option is right or wrong
  1. 1
    Plan the slots

    Before anything is written, a script fixes each question's syllabus point, difficulty, SL or HL, and which letter will be right. So every topic gets its share, and the right answers are spread evenly across A to D.

  2. 2
    Write

    The writer model drafts each question from its syllabus point, with that topic's note and existing questions in front of it so it does not repeat them. It writes the explanation for every option.

  3. 3
    Solve it blind

    The examiner, a second model, answers every question without seeing the key. If its answer differs, the question is wrong or unclear, and it is fixed or replaced. In maths, a script also recomputes each numerical answer.

  4. 4
    Check and fix

    The examiner then checks each question against the subject guide, the notes, the textbooks and the rest of the bank, and rewrites what is weak.

    What it has caughtAnswers already worked out in the notes. A right answer you could spot because it was the longest. A wrong option that was the right answer written another way. An SL question that needed an HL method. "Made-up" companies that turned out to be real.

  5. 5
    Run the scripts

    Before anything goes live, scripts flag a right answer much longer than the others, the same letter right too many times in a row, and broken or doubled fields.

  6. 6
    Live, and still open

    A mistake reported by a student or teacher is checked and fixed in the bank.

9,555questions: 8,395 IB, 760 SAT and 400 AP
About 40%of the latest 1,247 drafts were rewritten or replaced by the examiner before release
2,593questions in two recent batches, in which the blind examiner found no wrong answer key: what it fixed was everything else

How a note is written.

There is one note for each topic of the syllabus, 307 in all. This is how the IB notes are made: written from the subject guide, checked against what the exam asks and what the textbooks teach, then read by a second, separate pass whose job is to take things out.

educerie.com/notes/ib-diploma/biology/…/A1.2-nucleic-acids
The IB Biology A1.2 Nucleic acids note: the syllabus points it covers listed down the side, and a summary of the topic.

What every note has

  • ✓What you must be able to do: the guide's points for the topic (boxed above)
  • ✓In one breath: the whole topic in a few lines
  • ✓A numbered section for each point, with figures drawn in code
  • ✓Check your understanding: tick off what you can now do
  • ✓Practice questions on that topic, to finish
  1. 1
    Map the syllabus

    Every point the guide lists for the topic becomes a line in "What you must be able to do" and a section of the note, so nothing the guide asks for is left out.

  2. 2
    Write

    Drafted in plain words, one section per point, with diagrams drawn in code. Maths and Physics are typeset in LaTeX, as in a textbook.

  3. 3
    Check against three sources

    The subject guide, for coverage. The published question bank, for how the topic is really examined. Standard textbooks, for depth and accuracy: a note teaches what the main course books teach, not only the guide's bare list. The books are read only to check; nothing is copied from them.

    What it has caughtA Biology note that said immunofluorescence is done in a living cell. A Physics worked example with the wrong answer. A diagram with DNA twisting the wrong way.

  4. 4
    Review by a separate pass

    A second pass reads the checked note and takes out what should not be there. It cut about a third of what the checks had added: a book's example with the numbers changed, claims about what the mark scheme says that could not be backed up, and material from outside the syllabus.

  5. 5
    Run the scripts

    Before a note is published, scripts check its structure, that every figure exists and is numbered, and that its maths renders. The diagram tool refuses to save a figure whose labels collide.

228IB notes checked and reviewed this way in October 2026
About halfhad at least one real error, found and fixed by the check
About a thirdof what the checks added was then taken out again by the review
educerie.com/notes/ib-diploma/biology/…/A1.2-nucleic-acids
Figure 1 of the Nucleic acids note: a phosphate group, a pentose sugar and a nitrogenous base, drawn as a circle, a pentagon and a rectangle and labelled.

Diagrams drawn in code, then checked.

  • ✓Drawn by a program, to scale, not generated as a picture
  • ✓No label allowed to collide with another
  • ✓Every one checked by a second pass against its question or note

On the 848 diagrams in the question bank, that check fixed 188: curves shifted the wrong way, axes not to scale, current flowing backwards.

Mock papers to the real blueprint.

210papers in Biology, Chemistry, Physics, Maths AA and Economics, ten of every paper
  • ✓Built to each paper's real structure: sections, marks and time
  • ✓Reviewed by a second examiner pass, which rewrote between a quarter and a half of the questions
  • ✓Each with its mark scheme
  • ✓The grade it gives is an estimate, from estimated boundaries

Marking, honestly.

  • ✓Multiple choice is marked the moment you answer, against a checked key
  • ✓Written answers you mark yourself, point by point against the mark scheme

The AI marker is off

We built an AI marker and tested it against careful marking. It agreed on 93% of points in Biology and 91% in Economics, below our bar of 95%, and too often gave marks that were not earned. So it is switched off.

For students, it all connects.

  1. NoteEnds with questions on what it taught.
  2. QuestionsEvery answer explained, including why each wrong option is wrong.
  3. ConstellationA star for each right answer; three mistakes take one back.
  4. PlanEach topic comes back 2 days, 1 week and 3 weeks after you learn it, missed questions first.
  5. Mock paperMarked against its scheme, it points to what to go back to.

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Experienced examiners reviewing samples of our questions

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