IB ESS IA 2026: The Six Criteria You Must Understand

You find an ESS Internal Assessment guide online, follow its six headings, and begin planning your investigation. But the rubric in that guide may belong to a course that is no longer being assessed.

Environmental Systems and Societies (ESS) changed substantially for first assessment in May 2026. The revised IA still involves an individual investigation, but its assessment criteria have been reorganised, its maximum report length is 3,000 words, and a new requirement asks students to examine tensions between perspectives on an environmental strategy.

First, Check Which ESS Course Applies to You

According to the International Baccalaureate's ESS curriculum update, the revised course began teaching in August 2024 and was assessed for the first time in May 2026.

Under the revised assessment model, the individual investigation is worth 25% of the final ESS grade at SL and 20% at HL. Both levels use the same six IA criteria, for a total of 30 marks. The IB allocates 10 hours to the investigation, and the report has a maximum of 3,000 words.

As the IB's 2026 examiner instructions explain, teachers mark the work, which is then subject to external moderation.

The Six IB ESS IA Criteria for 2026

The current assessment structure is:

Criterion	What it assesses	Maximum marks
A: Research question and inquiry	Environmental context and a focused research question	4
B: Strategy	An environmental strategy and tensions between perspectives	4
C: Method	An appropriate, repeatable method yielding sufficient data	4
D: Treatment of data	Clear presentation and correct processing of relevant data	6
E: Analysis and conclusion	Interpretation of data and a supported answer to the question	6
F: Evaluation	Limitations, improvements and unresolved questions	6
Total		30

The breakdown is explained in Science Sauce's updated ESS IA guide and a 2026 rubric overview from RevisionDojo.

The earlier ESS IA also had six criteria and 30 marks. What changed was the criteria themselves and the distribution of marks, not simply the total. Advice referring to Identifying the Context, Planning, Applications or Communication as separate marked criteria belongs to the previous framework.

Criterion A: Research Question and Inquiry, 4 Marks

Criterion A connects the investigation to a meaningful environmental issue. A student needs sufficient background research to explain the issue and a focused question that can be investigated using relevant evidence.

Before finalising it, check whether you can identify what will be measured or examined, where the evidence will come from, and how that evidence can support a conclusion within the available time and word limit.

The context should make the inquiry necessary and understandable, with sources that readers can trace.

Criterion B: Strategy and Tension, 4 Marks

The IB's curriculum update explains that the additional criterion asks students to examine tensions between perspectives and how these can affect the environmental or societal outcomes of a strategy related to the issue under investigation.

Criterion B requires an existing or developing strategy addressing an environmental issue linked to your research question. You must then explain a tension arising from different perspectives, which could involve environmental, economic, social, cultural or political concerns.

Merely saying that a strategy has advantages and disadvantages is not the same as explaining a tension. Identify the perspectives, what each prioritises, why they conflict, and how that conflict matters for possible outcomes. Ground the account in reliable evidence rather than assigning opinions to unnamed groups.

Importantly, the strategy does not have to be the exact intervention tested in your data collection. It must be meaningfully connected to the environmental issue. Science Sauce's criterion explanation makes this distinction explicit.

Criterion C: Method, 4 Marks

Your method should be suitable for answering your question and detailed enough for another person to follow. Describe how information is selected or collected, what is recorded, and how the resulting data will be processed.

ESS investigations can involve primary or secondary data and qualitative or quantitative approaches. The method must still generate or select sufficient evidence that you can analyse in response to your own research question.

Explain relevant choices about sampling, measurement, consistency and data sources, while keeping the approach proportionate to your inquiry.

Criterion D: Treatment of Data, 6 Marks

Criterion D focuses on presenting raw and processed information clearly and processing it accurately enough to address the research question.

Make units, labels and processing steps intelligible. Check that any transformations of the data are correct and that the output answers the question you actually asked.

A visually polished graph cannot compensate for processing that does not fit the inquiry. Likewise, extensive calculations are not inherently better than a small, well chosen set of relevant analyses.

Criterion E: Analysis and Conclusion, 6 Marks

This criterion asks you to interpret your results, explain relevant patterns or trends and reach a conclusion supported by the analysis.

Good analysis makes the strength and limitations of the evidence visible. Consider relevant issues of bias, reliability, validity and uncertainty rather than presenting every observed pattern as conclusive. It should not introduce claims that were never examined or treat correlation as proof of causation. Where the evidence is inconclusive, explain that limitation instead of overstating certainty.

Criterion F: Evaluation, 6 Marks

Evaluation requires more than a familiar list of human errors or a promise to collect more data next time.

Identify specific weaknesses in the investigation, assess how they affect the conclusion, and explain improvements that address those weaknesses. Also consider unresolved questions emerging from your work and why they matter for the answer you reached.

A weakness is worth discussing because it changes how confidently the research question can be answered, not merely because something could have been done differently.

Can ESS Students Collaborate on the IA?

Yes, within defined boundaries. The revised IB curriculum update allows students to collaborate in small groups and use similar methodologies in appropriate circumstances. The investigation and submitted report must nevertheless remain individual.

Students must have distinct research work and unique data, with relevant variables differentiated where a similar method is shared. Science Sauce's guidance describes the collaboration limit as groups of no more than three.

Collaboration does not permit shared paragraphs, copied analysis or a joint report submitted under different names.

What the 3,000 Word Limit Means for Planning

The revised ESS IA has a 3,000 word maximum, compared with the older 2,250 word limit. Plan space for your environmental context, Criterion B discussion, method, results, interpretation and evaluation. There is no need to assign identical word allowances to six criteria, since the demands and maximum marks differ.

Ask your teacher which items are excluded from the official count, how to treat appendices and what submission conventions your school follows. Do not assume rules from another subject apply automatically.

Use your own assessment calendar to protect time for methodology checks, data gathering, processing and teacher feedback. For a broader planning framework, read Koncepts' IB IA Timeline.

How to Spot an Outdated ESS IA Guide

Before trusting an online resource, inspect three details: the assessment year, the criterion names and the word limit.

For instance, Nail IB's ESS IA guide, published in January 2023, describes the earlier system with separate criteria such as Planning, Applications and Communication. Those labels do not match the rubric for first assessment 2026.

Clastify's ESS exemplar collection may still be useful for studying how investigations are written, but check the session and rubric attached to any sample before treating its marks as a current benchmark. Revision Village's ESS resources focus on wider course revision and should not be mistaken for the official IA marking guide.

An older example can teach presentation or investigation skills.

A Better Way to Start Your ESS Investigation

Before drafting a complete report, prepare a short planning record that answers these questions:

1. What is the environmental issue, and what credible evidence establishes its significance?
2. What precise research question can available data help answer?
3. Which existing or developing strategy addresses that issue, and what tensions between perspectives does it create?
4. Can the method be followed and produce sufficient, relevant data?
5. What processing will allow the evidence to answer the question?
6. What limitations might affect the conclusion, and how will you evaluate them?

Take the plan to your teacher for guidance on feasibility, safety, academic integrity and the applicable rules.

Understand the Rubric Before You Write

The revised ESS IA rewards scientific inquiry alongside an informed understanding of environmental decisions. If you are beginning the investigation now, start with the current guide, not a template from an earlier assessment cycle. Build an individual investigation you can explain and support.

For wider IB Diploma study support, start free with Koncepts. Use your teacher's official ESS documents for the IA itself, as Koncepts does not currently offer a dedicated ESS subject hub.

Related Blogs

For coursework planning, read IB IA Timeline: Plan Every Deadline Without Collisions. For a broader overview of common errors, see IB Internal Assessment Mistakes Students Must Avoid, and for school level planning, explore Stop Chasing IA Deadlines: A Two Year Plan That Works.