- How IB Assessment Works
- Who Marks IB Work: Teachers, Moderators and Examiners
- How to Read an Assessment Criterion
- Best Fit: How Markers Choose a Level
- Criteria Examples: What Does 'Criterion B' Mean?
- Skills That Appear Across Subjects
- What Separates the Top Levels from the Middle
- How to Use Criteria to Raise Your Marks
- From Criteria Marks to a 1-7 Grade
- Make Sure You Have the Right Criteria
Quick Answer
IB assessment criteria are the published descriptors used to mark coursework and many exam answers. Each criterion, labelled A, B, C and so on, assesses one skill and has levels of achievement. The marker chooses the level that best fits your work, then a mark within it. Criteria marks are added, weighted with your other components, and converted to a 1-7 grade.
What You'll Learn
- Each criterion assesses one skill, and the letters mean different things in each component
- Markers use best fit: the level whose description matches your work overall
- Teachers mark internal assessments and the IB moderates a sample; examiners mark exams
- Raw marks become 1-7 grades through grade boundaries set after each session
- Several courses changed recently, so check you are using the criteria for your exam year
How IB Assessment Works
The IB marks your work against fixed standards rather than ranking you against other students, an approach it calls criterion-related assessment. Every component in a subject guide comes with its own marking tool, and knowing which one applies tells you what the marker is looking for.
- Assessment criteria (what many students call the rubric): used for coursework such as internal assessments, orals and the extended essay, and for some exam papers. Each criterion covers one skill and has level descriptors
- Markbands: used for many extended exam answers. One set of level descriptors describes the overall quality of a response
- Markschemes: used for short-answer and structured questions. They list the specific points, methods or answers that earn each mark
- Assessment objectives: listed in every subject guide, they describe the skills the course assesses, such as knowledge and understanding, application and analysis, and synthesis and evaluation. Criteria, markbands and markschemes are all written to test them
Pro Tip
Get the criteria for every major piece of work from your teacher or the subject guide. Read them before you start and keep them open while you work.
Who Marks IB Work: Teachers, Moderators and Examiners
IB marking happens in two ways, and the difference matters when you plan your work.
- Internal assessment: your teacher marks your work against the published criteria. The IB then takes a sample from your school and a moderator re-marks it. If the teacher's marks are consistently too high or too low, the school's marks for that component can be adjusted
- External assessment: exams and some coursework, such as the extended essay and the Language A HL essay, are marked by examiners appointed and trained by the IB. Your teacher does not mark these
- Monitoring: examiners' marking is checked by senior examiners during the marking session, to keep standards consistent
- Grade award: after marking, senior examiners set the grade boundaries that turn marks into grades
How to Read an Assessment Criterion
Criteria look similar across subjects. Each has a letter and a name, a maximum mark, and level descriptors that describe work in each mark range. Some components also give a guiding question for each criterion.
- Read every level, not just the top one. The differences between adjacent levels show exactly what moves work up
- Underline the command verbs: describing is lower than analysing, which is lower than evaluating
- Note the qualifiers, such as limited, adequate, good and excellent, or some, mostly and consistently. They mark the steps between levels
- Look for specific requirements, such as a focused research question, references, processed data or a link to a global issue
- Check the maximum mark: a 12-mark criterion deserves more planning time than a 4-mark one
Best Fit: How Markers Choose a Level
IB markers use a best-fit approach. They read the whole piece of work, then choose the level whose descriptor matches it best overall, even if a few details match a different level. Within that level, they award a higher mark if the work clearly and fully fits the descriptor, and a lower mark if it only just fits. Each criterion is judged separately, so a strong piece of work can still score poorly on one criterion it neglects.
- Strength in one aspect of a criterion can partly balance weakness in another aspect of the same criterion
- Criteria are not averaged; each is marked on its own evidence
- A mark of 0 is given when the work does not reach the lowest descriptor
- Being between two levels is normal: the marker decides which description fits better overall
Criteria Examples: What Does 'Criterion B' Mean?
Letters are local to each assessment. Criterion B in one component has nothing to do with criterion B in another, so always read the criteria for the exact component you are working on. Some current examples:
- English A individual oral (40 marks): A, knowledge, understanding and interpretation; B, analysis and evaluation; C, focus and organisation; D, language. Each is worth 10 marks
- English A Paper 2 from May 2026 (25 marks): five criteria worth 5 marks each, with analysis split into B1, analysis of authorial choices, and B2, comparative analysis
- Language B individual oral (30 marks): A, language (12 marks); B1, message in the presentation (6); B2, message in the conversation (6); C, interactive skills (6)
- Extended essay from May 2027 (30 marks): A, framework for the essay (6); B, knowledge and understanding (6); C, analysis and line of argument (6); D, discussion and evaluation (8); E, reflection (4)
- MYP subjects: every subject group uses four criteria, A to D, each marked from 0 to 8. Criterion B is, for example, inquiring and designing in sciences and investigating in individuals and societies
Pro Tip
If you searched for 'criterion B', check the subject and the component first. In the English A oral it is analysis and evaluation; in the extended essay from 2027 it is knowledge and understanding; in MYP sciences it is about designing an investigation.
Skills That Appear Across Subjects
Specific criteria vary, but most reward the same underlying skills, which follow the assessment objectives:
- Knowledge and understanding: accurate, relevant content and correct terminology
- Application and analysis: using knowledge to explain how and why, not just stating facts
- Synthesis and evaluation: weighing evidence, making supported judgements and recognising limitations
- Communication and organisation: a clear structure, a focused argument and an appropriate register
- Engagement and reflection: independent thinking and, in some components, reflection on your own process
What Separates the Top Levels from the Middle
The same contrasts appear in descriptor after descriptor. Knowing them helps you target improvements:
- Analysis vs description: lower levels describe what happens; higher levels explain how and why
- Evaluation vs assertion: higher levels justify judgements and consider limitations
- Integration vs separation: top work connects ideas; weaker work presents them in isolation
- Precision vs vagueness: higher levels use specific evidence and exact terminology
- Depth vs breadth: top marks come from developing selected points well, not touching on everything
How to Use Criteria to Raise Your Marks
Criteria are most useful as a planning and checking tool, not something you read once.
- 1Before you start: turn each criterion into two or three checklist questions in your own words
- 2While planning: map each section of your work to the criterion it serves; anything that serves none is a candidate to cut
- 3After a draft: mark it yourself against every criterion, writing down the level and one reason
- 4Get a second opinion: your teacher can mark a coursework draft, and a tutor or classmate can mark a practice answer independently; then compare
- 5Study marked examples: your teacher can access IB examples of student work with marks and comments, which show what each level looks like
- 6After feedback: link each comment to a criterion, so you know which descriptor you are aiming for next time
Pro Tip
A checklist built from the criteria is the fastest final check before you submit anything.
From Criteria Marks to a 1-7 Grade
Criteria marks are not your grade. For each subject, your marks on every component are weighted as the subject guide sets out and combined. Grade boundaries, set by senior examiners after each exam session, then convert the result into a grade from 1 to 7. Boundaries can move slightly between sessions so that a grade represents the same standard even when a paper was harder or easier. For the diploma, your six subject grades give up to 42 points, and the extended essay and theory of knowledge combine for up to 3 more, a maximum of 45. You need at least 24 points, along with other conditions, to be awarded the diploma.
Make Sure You Have the Right Criteria
Several IB courses changed recently, and aiming at an older set of criteria means aiming at the wrong target. Check the first-assessment year on the guide your teacher uses. Recent and upcoming changes include:
- Extended essay: new criteria from May 2027 (guide published in February 2025, first taught from August 2025), so November 2026 is the last session on the old criteria
- Language A courses, including English A: new Paper 2 criteria from May 2026; the individual oral is unchanged
- Biology, chemistry and physics: new guides first assessed in May 2025
- Environmental systems and societies, global politics, and sports, exercise and health science: new guides first assessed in May 2026
- Computer science, design technology, psychology and visual arts: new guides first assessed in May 2027
- History: new guide first assessed in May 2028
- Language B, language ab initio, both mathematics courses and dance: new guides first taught from August 2027 and first assessed in May 2029
- World religions: replaced by a new course, religion and society, first taught from August 2027 and first assessed in May 2029