Eight steps to your ESS IA
The internal assessment (IA) is the biggest single piece of work in the course, worth a fifth or a quarter of your grade.
It is also, genuinely, the interesting part. You choose somewhere real, find out what is happening to it, and argue something about what should be done. What follows is the order we suggest doing that in, and why.
The process
Each step produces something the next one needs. The word counts are what we suggest spending when you eventually write that section up, not what to write now.
The IB sets no section word counts and no required order. These figures are ours, and so is the order. The next section explains the one part of it that will surprise you.
Why the real-world strategy comes third
Most people design their fieldwork and then, somewhere near the end, add a section about stakeholders. we suggest it goes before the method, and it is the most consequential decision in this whole guide.
Here is the reasoning. A fieldwork report has a natural shape that assembles itself: transect, quadrats, an index, a statistical test, a conclusion. That shape is what almost every example online looks like. What it never produces on its own is a real-world strategy and the people arguing about it.
So that layer is not something you can lose. It won't appear unless you deliberately put it there. Settle the argument first and your data gets collected to serve it. Leave it until just before the draft is due and you will be hunting for a strategy that fits results you already have.
Choose the argument before you choose the measurements, and your investigation will have something to be about.
What makes this an ESS investigation
ESS is an interdisciplinary subject in the Diploma, and the investigation is where that has to be visible. Three ideas run through the course, and a strong report carries all three.
Your variable sits inside something with inputs, outputs, stores and feedbacks. Not a list of measurements.
People want incompatible things, and what happens to an environment depends on how that gets resolved.
Whether what is happening can carry on, and at whose expense.
One criterion asks you to name a real-world strategy addressing your issue and explain a tension between the people who disagree about it. Four marks out of thirty, and it is the only part of the report that could not appear in a Biology or a Geography investigation.
That is not a reason to avoid biological or geographical methods. Quadrats, water chemistry and questionnaires are all fine, and the guidance says so. It is a reason to make sure there is an environmental issue and a live argument wrapped around whichever method you choose.
How to use this guide
Work through the steps in order. Each one opens with what you should be arriving with and closes with a checklist, and the checklist is the point rather than the decoration. It is the only part that asks about your investigation rather than explaining things in general.
Tick honestly. An untickable box is not a mark against you, it is simply the next thing to go and do. If you are signed in, your ticks are saved and your teacher can see how far along you are.
A ski piste in the French Jura
The investigation compares plant species diversity on a managed ski piste with the montane forest immediately beside it. Fifteen quadrats per site, percentage cover recorded species by species, and three abiotic variables measured alongside as candidate explanations: canopy cover, soil compaction and soil moisture.
It was done at Mijoux, at 1,333 m in the Monts Jura, on the French side of the border about an hour from Geneva. That altitude matters: it is below the treeline, so the ground beside the piste is forest rather than alpine meadow, and the comparison is between a slope held open by machinery and one that was never cleared.
What makes it an ESS investigation rather than a biology practical is what is happening around it. The resort sits inside a €31 million development plan that funds new lifts at one end and, at the other, marks certain runs to be left ungroomed and allowed to go back to nature. The nature reserve wants the forest returning; the commune needs winter visitors for a village economy of a few hundred people; a handful of graziers lose summer pasture whichever way it goes. A real-world strategy, and people with genuinely incompatible goals arguing about it.
It runs through every step because it went wrong in useful ways, and none of that has been tidied up:
- A question nobody could have answered · step 2The first attempt was “how does skiing affect biodiversity?”, no place, nothing measurable, unanswerable in 3,000 words.
- A question that assumed its answer · step 2The second built “disturbance” into the wording, then the data went the other way and the framing fought the finding all the way to the conclusion.
- The wrong abiotic variable · step 4Light was measured with a lux meter: two readings, under moving cloud, useless for correlating. Canopy cover was the stable version of the same thing.
- Enough data for one statistic, not another · step 4Fifteen quadrats per site clears a t-test and falls short of a standard error. Noticed afterwards rather than planned for.
- An outlier that was nearly deleted · step 5One forest quadrat scored far above the rest. It was a gap in the canopy, and it became the clearest evidence for what drove the whole pattern.
- One wrong word, everywhere · step 8An early draft called the site “alpine”. At 1,333 m in the Jura it is below the treeline, and the word had reached the title, the question and the conclusion.
Every one of those is more use to you than a study where everything worked first time.
One thing before you start
You will get one round of written feedback on a full draft. Your teacher can comment on what is strong and what is weak, but they cannot correct it, and there is no second draft after that.
Which means two things. Hand over something complete rather than something polished, because feedback on three finished sections and five missing ones is feedback on three sections. And aim for 2,900 words rather than 3,000, because that feedback will almost certainly ask you to develop something, and at the ceiling the only way to do that is to delete something good.
Most advice tells you to choose a topic. We think you should choose a place, and step 1 explains why.
Start step 1The ski piste investigation used throughout this guide is a teaching reconstruction. The location, sampling design, plant records and soil data come from real fieldwork at Mijoux in the French Jura. Canopy cover measurements were added to illustrate good practice and were not part of the original fieldwork. Photographs are the author’s own, taken at the site. It is written to show how an ESS investigation is built, not to report findings about biodiversity at this site.