IB Maths IA Criteria Guide
The IB Maths IA is marked out of 20 across 5 criteria. Learn exactly what examiners look for.
These plain-English explanations are based on the assessment criteria in the official IB Mathematics: analysis and approaches and Mathematics: applications and interpretation subject guides (first assessment 2021). Check the current subject guide, available through your school's IB Programme Resource Centre, for the exact wording your teacher will mark against.
A – Presentation 4 marks
How well your IA is organised and structured.
Mark Descriptors
| Marks | Descriptor |
|---|---|
| 0 | The IA does not reach the standard described by the descriptors below. |
| 1 | The exploration has some coherence but is difficult to follow. Few graphs, tables, or diagrams are included or are poorly labelled. |
| 2 | The exploration has some coherence. Some graphs, tables, or diagrams are included and are appropriately labelled. |
| 3 | The exploration is generally easy to follow. Graphs, tables, and diagrams are included and are mostly properly labelled. |
| 4 | The exploration is easy to follow. All graphs, tables, and diagrams are appropriately labelled. The work is legible and is not affected by cosmetic errors. |
Examiner example: A strong Grade 7 IA flows naturally from introduction → exploration → conclusion, with every graph clearly titled and every variable defined when first introduced.
Do
- Use clear headings and subheadings
- Label every axis on every graph
- Number all tables and figures
- Keep to 12–20 pages (not including bibliography)
- Use consistent font and layout
- Include a clear introduction and conclusion
Don't
- Leave unlabelled graphs or tables
- Write a wall of text with no structure
- Go over 20 pages - more is not better
- Use different fonts/styles throughout
- Submit a poorly scanned or illegible document
B – Mathematical Communication 4 marks
How accurately and precisely you use mathematical language, notation, and representation.
Mark Descriptors
| Marks | Descriptor |
|---|---|
| 0 | The IA does not reach the standard described by the descriptors below. |
| 1 | Some mathematical communication is used but it is limited, inaccurate, or inconsistent. |
| 2 | Some appropriate mathematical communication but used with some inconsistency or inaccuracy. |
| 3 | Appropriate mathematical communication used with some inconsistency or occasional inaccuracy. |
| 4 | Appropriate mathematical communication throughout, used accurately, consistently, and precisely. Multiple forms of representation are used where appropriate. |
Examiner example: Instead of "I used the formula for a curve", write: "The quadratic model f(x) = ax² + bx + c was fitted to the data, where x represents time in seconds and f(x) represents height in metres."
Do
- Define all variables and notation when first used
- Use correct mathematical symbols (∑, ∫, θ etc.)
- Move between representations: equation → graph → table
- Write equations using proper formatting
- State units where applicable
- Use formal mathematical language
Don't
- Mix notation styles inconsistently
- Leave variables undefined
- Use informal language ("I timesed x by 2")
- Only present results without showing working
- Use calculator notation (e.g. E notation) in formal writing
C – Personal Engagement 3 marks
Evidence that you have genuinely engaged with the mathematics - your curiosity, creativity, and independent thinking.
Mark Descriptors
| Marks | Descriptor |
|---|---|
| 0 | The IA does not reach the standard described by the descriptors below. |
| 1 | There is evidence of limited or superficial personal engagement. |
| 2 | There is evidence of some personal engagement but this is not well developed. |
| 3 | There is evidence of significant personal engagement. Independent thinking is apparent. The exploration is creative and/or original. |
Examiner example: "I became interested in this topic after fracturing my arm - I wanted to understand mathematically how the surgeon chose the size and angle of the metal plate" - this is genuine, verifiable personal engagement.
Do
- Explain in the introduction why this topic genuinely interests you
- Make your own choices within the exploration
- Collect your own data where possible
- Add your own observations, not just textbook facts
- Show genuine curiosity: "I wondered whether..."
- Extend the standard theory in your own direction
Don't
- Copy a standard textbook exploration unchanged
- Use only pre-prepared datasets without personal context
- Write in a detached, impersonal tone throughout
- Just summarise what others have done without adding your own analysis
D – Reflection 3 marks
Critical thinking about your process, results, and limitations - not just at the end, but throughout.
Mark Descriptors
| Marks | Descriptor |
|---|---|
| 0 | The IA does not reach the standard described by the descriptors below. |
| 1 | There is evidence of limited or superficial reflection. |
| 2 | There is evidence of meaningful reflection. Some consideration is given to the significance, limitations, or possible extensions. |
| 3 | There is substantial evidence of critical reflection. Results are compared and discussed in depth. Meaningful consideration is given to limitations and extensions. |
Examiner example: Weak: "My model had some limitations." Strong: "The logistic model assumes a constant carrying capacity, but in reality the environment changes seasonally - a possible extension would be to model K as a periodic function."
Do
- Comment on what results mean - not just what they are
- Acknowledge assumptions your model makes
- Identify specific limitations
- Suggest genuine extensions
- Reflect throughout, not just in the conclusion
- Discuss whether results matched your expectations
Don't
- Write generic comments like "My IA was limited because maths is hard"
- Only reflect in the conclusion
- Claim your model is perfect with no limitations
- Confuse limitations with errors
E – Use of Mathematics 6 marks
The accuracy, relevance, and sophistication of the mathematics in your exploration.
Mark Descriptors
| Marks | Descriptor |
|---|---|
| 0 | The IA does not reach the standard described by the descriptors below. |
| 1 | Some relevant mathematics is used but it is mainly descriptive and contains significant errors. |
| 2 | Some relevant mathematics is used. It is mostly accurate. Limited mathematical sophistication is shown. |
| 3 | Relevant and accurate mathematics is used but the mathematical sophistication is limited, containing only routine procedures. |
| 4 | The mathematics used is mostly relevant, accurate, and shows some sophistication. |
| 5 | The mathematics used is relevant, accurate, and shows some sophistication. Thorough understanding of the relevant mathematics is demonstrated. |
| 6 | Relevant, accurate, and sophisticated mathematics is used. Thorough understanding is demonstrated. The mathematics goes beyond what is required for the course level. |
Examiner example: An SL AI student who models population growth using a logistic differential equation and interprets the parameters in context will score better than one who calculates a few percentages and draws a bar chart.
Do
- Use mathematics that is at or beyond your course level
- Show all steps - don't just quote a final answer
- Connect your mathematics to the real-world context
- Use multiple techniques where appropriate
- Check your calculations - accuracy is marked
Don't
- Rely solely on basic arithmetic or simple statistics at HL
- Use maths that is disconnected from your aim
- Present calculator outputs without showing the method
- Make errors in basic algebra that undermine your results