IB Diploma Glossary for Parents: The Terms That Change Decisions
By Renzo Diaz·3 min read
Most IB terms matter because they change a practical decision, not because they're jargon worth memorising for its own sake — a predicted grade can affect an application, a subject requirement can determine eligibility, an IA deadline can reshape a revision calendar. Reading a glossary entry alongside a student's actual school documents, not instead of them, is what makes a term useful rather than just familiar.
A school report or an admissions page can use a dozen IB-specific terms in a single paragraph, several of which sound interchangeable but aren't — a predicted grade and an achieved grade describe genuinely different things, and treating them as the same one produces the wrong read on how a student is actually doing.
A predicted grade can affect an application. A subject requirement can determine eligibility. An IA deadline can change the entire revision calendar. The terms are worth knowing because the decisions are real.
1. Twelve terms worth knowing on sight
Each of these shows up regularly in school reports and admissions pages, and each one is tied to a specific decision a parent might actually need to make.
| Term | Meaning | Why a parent should care |
|---|---|---|
| DP | The two-year Diploma Programme, usually for students aged 16 to 19 | Check whether a report concerns the DP or an earlier programme such as the MYP |
| HL / SL | Higher / Standard Level — 240 / 150 recommended teaching hours respectively | A university may require a named subject specifically at HL |
| AA / AI | Analysis and Approaches / Applications and Interpretation, the two DP Mathematics courses | Each exists at HL and SL; a requirement can name the course and the level together |
| IA | Internal assessment — a subject-specific component marked at school | The task and weighting vary genuinely by subject; ask for the relevant guide directly |
| Predicted grade | A school's own estimate of the final grade, sent with some applications | Ask what evidence and school policy actually support it — it isn't the final IB result |
| Grade boundary | A threshold converting performance into a grade for one specific assessment session | Not a timeless difficulty score, and not a universal mock-exam conversion table |
| Markscheme | The instructions used for awarding marks on a specific assessment | Check the method and evidence required, not just the final answer |
| Command term | An instruction word such as "justify," "show," or "evaluate" | It specifies the actual kind of response a question expects |
| GDC | Graphic display calculator | Its permitted use depends on the course and paper; output usually still needs supporting working |
2. The core terms, and what they actually add up to
TOK, EE and CAS appear constantly in DP documents, but their relationship to the final Diploma points isn't always obvious from the terms alone. TOK and the EE together are graded to produce up to three additional points on top of the six subject grades; CAS is required for the Diploma but contributes no points of its own — completion, not a grade, is what's assessed.
The IB's own passing criteria distinguish clearly between a total score and the actual award of the Diploma. Six subject grades plus the TOK/EE core can total up to 45 points, but at least 24 points and several further specific conditions — including a minimum grade in every subject — are all needed for the Diploma to actually be awarded. A headline total, on its own, doesn't tell you whether those other conditions are met.
Layer 1 — TOK
Theory of Knowledge — a core course graded with the EE, assessed through an exhibition and a 1,600-word essay
Layer 2 — EE
The Extended Essay — independent research up to 4,000 words; check whether the student's cohort follows the criteria first assessed in May 2027
Layer 3 — CAS
Creativity, Activity, Service — required for the Diploma, does not add points, assessed by completion rather than a grade
3. Three pairs of terms that are easy to confuse
A school percentage and an IB grade are not the same measurement, and converting one into the other by borrowing a boundary from an unrelated paper or session produces a number that looks precise but isn't actually meaningful — a test marked out of 100 at school is evidence of current performance, not a translated IB grade.
A predicted grade and an achieved grade are also genuinely different things: a prediction is an estimate submitted before final examinations happen, while an achieved grade is awarded only after the actual assessment. When a predicted grade changes, the useful question is what new evidence actually explains the change, not just noting that it moved.
Course suitability and university eligibility are a third pair worth separating. A student can learn well in one mathematics course while a specific target degree requires the other course entirely — checking the named subject, level, and grade on a degree's own current admissions page settles this far more reliably than assuming from the course a student happens to enjoy.
A school percentage is evidence of current performance. It is not, on its own, a translated IB grade.
4. The most useful question to bring to school
When a report contains an unfamiliar term, the productive question isn't "what does this mean" in isolation — it's what decision this specific measure actually supports, and what evidence would be enough to change that decision. A precise answer to that tells a parent whether to investigate a syllabus mismatch, a genuinely weak exam script, an approaching deadline, or a university admissions condition. A general answer like "work harder" doesn't point anywhere specific, and isn't actually responsive to what was asked.
Sources
Sources below are the IB's own current pages, checked directly in a browser.