IB ESS IA: 2026 criteria and fieldwork planning
For first assessment in 2026, the ESS investigation is marked out of 30 across six criteria. It contributes 25% at SL and 20% at HL, with a report limit of 3,000 words.
For first assessment in 2026, the ESS investigation is marked out of 30 across six criteria. It contributes 25% at SL and 20% at HL, with a report limit of 3,000 words.
The current criteria
| Criterion | Maximum |
|---|---|
| A: Research question and inquiry | 4 |
| B: Strategy | 4 |
| C: Method | 4 |
| D: Treatment of data | 6 |
| E: Analysis and conclusion | 6 |
| F: Evaluation | 6 |
| Total | 30 |
Use the guide for your examination session. These six criteria should not be mixed with an older 24-mark rubric or an invented four-by-eight-mark model. A raw IA score is not a guaranteed final subject grade.
Choose a question that the data can answer
Start with an environmental issue and narrow it to a measurable relationship or comparison. Specify the location or data source, variables and scope. For example, comparing water-quality measurements across sites requires a reason for selecting those sites and a method for handling differences in sampling conditions.
Separate the question from the desired conclusion. The investigation should still make sense if the results do not support the original expectation.
Plan fieldwork before collecting data
Record the sampling approach, equipment resolution, measurement procedure and any ethical or environmental constraints. A small pilot can reveal inconsistent measurements before the main collection begins. Retain the raw data and explain exclusions rather than deleting inconvenient observations.
Connect the investigation to a strategy
Discuss a relevant existing or developing response to the environmental issue and the tensions between stakeholder perspectives. Keep this discussion connected to the investigation; a generic paragraph about sustainability does not establish that connection.
Process, interpret and evaluate
Label tables and graphs with variables and units. Choose calculations that answer the research question. Explain what the results show, how uncertainty limits the conclusion, and whether a proposed improvement would reduce a specific limitation. Avoid a list of vague mistakes such as human error without explaining its effect.
The report must remain the student's own work. Use teacher feedback and the official descriptors to identify revisions; a checklist or automated estimate does not replace school assessment and IB moderation.