A Complete Guide to the Environmental Systems and Societies Internal Assessment

The IB Environmental Systems and Societies Internal Assessment – the ESS IA – is an individual investigation worth 25% of your final grade at Standard Level and 20% of your final grade at Higher Level. This page provides a clear, student-friendly guide to the ESS IA, including:

Practical tips to help you achieve top marks
A breakdown of all ESS IA assessment criteria (A–F)
Guidance on research questions, methods, and data analysis
Common mistakes and how to avoid them

What is the IB ESS Internal Assessment?

The ESS IA is a scientific investigation into an environmental issue. You will:

Identify a focused environmental problem
Develop a testable research question
Collect and analyze data
Draw conclusions based on evidence
Evaluate the strengths and limitations of your investigation

The final product is a written report of 3,000 words maximum. Students are allocated at least 10 hours in class to work on the ESS IA, but a good IA requires more time than that. Plan to spend many hours outside of school on your Internal Assessment.

Your IA should demonstrate both scientific skills and an understanding of environmental systems.

Below, you can find resources to develop, conduct, and evaluate high-quality Internal Assessments that earn good scores from IB ESS examiners like me. Follow my guidance in the slides and videos below to craft a successful Environmental Systems and Societies IA.

ESS IA Criteria Explained (A – F)

Your work is assessed using six criteria. Understanding these clearly is one of the easiest ways to improve your score.

ESS IA Criterion A: Research Question and Inquiry Explained

This criterion focuses on how clearly you define your investigation.

A strong ESS IA:

Identifies a specific environmental issue
Includes a focused, testable research question
Clearly defines independent and dependent variables at a specific location

Example (strong):
How does distance from Route 66 affect particulate matter deposition on leaves?

Common mistake: Questions that are too broad or descriptive (e.g. “How does pollution affect the environment?”)

Follow my guidance in the slides above and the video below to develop a strong research question and define your investigation’s central environmental issue.

Key takeaway: Use measurable variables and a defined location or context to establish a clear foundation for your ESS Internal Assessment.

ESS IA Strategy Explained

In the Strategy section of the ESS IA, students describe an existing or developing strategy that addresses an environmental issue linked to the research question. Students must explain economic, social, cultural, political or environmental tensions between stakeholders that impact the effectiveness of the strategy.

ESS IA Methodology: What to do

Internal Assessment examiners want students to design a repeatable method that uses appropriate sampling strategies to collect enough relevant data to respond to the research question. Variables must be manipulated and controlled, and the method must include safety and ethical considerations.

ib-sciences-experimentation-guidelines-en_235d471c-0bca-4edf-8ce9-47bdb2b92113 Download

ESS IA Data Presentation and Processing

In the Criterion D Treatment of Data section of the ESS IA, students are expected to create clear, high-quality data tables and graphs that show trends and patterns in their data. They use statistical tools to analyze data collected during the investigation.

For more guidance about specific statistical tests to perform on the data collected for the Internal Assessment, check out the “Data and Statistics in ESS” section below.

How to Write the ESS IA Analysis and Conclusion

Criterion E of the ESS IA requires students to identify and explain all patterns and trends in data, supporting their analysis with specific evidence from their results to reach a conclusion about the research question. They must explain bias, reliability, validity, and uncertainty in their results.

ESS IA Evaluation Explained

In this final section of the ESS Internal Assessment, examiners want students draw on what they wrote about bias, reliability, validity and uncertainty in their analysis to evaluate specific limitations in their methodology. Students are then expected to explain how each limitation may have affected the results, and they should describe any new or unresolved questions that arose during the investigation.

Common Mistakes in ESS Internal Assessments

To earn high marks on the ESS IA, students should avoid these things:

vague or unfocused research questions that don’t specify variables or a location
limited discussion of stakeholder tensions in the strategy section
few or no control variables in the method
not enough data collected
inadequate statistical analysis of data
weak evaluation

Practical Work

Students are required to complete several hours of practical work for IB Environmental Systems and Societies. Practical work in ESS consists of laboratory experiments and investigations, virtual simulations, data visualizations, and – my personal favorite – ecological field work. If/when you’re in the field, a few of these notebooks are really helpful because the pages are waterproof and they’re small enough to fit in a pocket.

Over the years, I have developed an extensive program of activities for each topic in the ESS syllabus. You can find some of them below, which I add to this page as I edit them. Editable versions of them are also available at my TPT store by the same name: Mr Kremer Science.

Data and Statistics in ESS

This is a helpful video for your ESS IA, not because it shows you how to do different statistical tests – it doesn’t – but because it teaches you what different stats mean about your experimental results.

Pearson’s correlation is used to understand the relationship between variables. This brief video provides a nice summary that you can apply to your IA data when you’re dealing with continuous variables like those along an environmental gradient.

I like this video because the examples used are fairly easy to connect to the fieldwork you might do in your ESS IA. It includes p-values, the T-test, chi-squared, and the ANOVA test. The author Greg Martin has a nice stats cheat sheet you can download for free, too.

You may find this video about measures of variability helpful as you write section D of your ESS IA. It goes through the mathematics and the meaning within data sets. You can apply these to the data you collect in your internal assessment.

Collaborative Sciences Project

Happy learning!

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