Design your method
A research question, a place, and a tension. That last one is more useful here than it looks: knowing what each side of the argument would want to see is how you work out what is worth measuring.
- A method a stranger could follow
- Enough planned data to answer your question
- Your variables, named and justified
- Safety and ethics specific to what you are doing
Your method is an instruction manual, written afterwards.
Two things at once, and students usually get one of them. It has to be complete enough for someone else to follow, and it has to be a record of what you actually did rather than a plan for what you intend to do. Anything you changed in the field belongs in it.
This criterion is two questions. Both must be yes.
Could a third party replicate your investigation from what you wrote, with you nowhere near them? If any step needs you standing there to explain it, the answer is no.
Does the method generate enough to answer the question you asked? Not enough data here hurts you again in steps 5 and 6, when there is nothing to find a pattern in.
Fail either and you are in the 1–2 band, however well the other one is done. There is no partial credit and no ladder of command terms here. It is unusually blunt for an IB criterion, and unusually easy to check.
Everything below is how we suggest you actually do it.
Write it as a record, not a plan
The guidance is explicit that the method should not be a proposal but an account of what was done. That means past tense throughout, and it means including the things that went differently from how you imagined them.
If you ran a pilot and changed your interval afterwards, say so. If the third site was inaccessible and you moved it, say so. Those are not admissions of failure; they are what makes the account true, and step 7 will thank you for them.
Standard protocols should be cited rather than copied out. Nobody needs the Winkler method reproduced in full; a reference to it is enough.
Plus correct scientific names for any organism. Vaccinium myrtillus, not bilberry.
How much data is enough
The mark scheme says "sufficient" and leaves you to work out what that means. It is not a mystery, though, because the statistics you will run in step 5 have their own thresholds, and those set the floor.
| Along a gradient | at least 5 intervals |
| Repeats at each point | at least 3 |
| Within each zone | 3 minimum, 5 better |
| Survey responses | at least 30 |
| For a standard deviation | 5 or more |
| For a t-test | 10 or more |
| For a standard error | 30 or more |
Decide which test you will run before you go out. Discovering afterwards that you have eight readings and needed ten is a bad afternoon.
Fifteen quadrats at each of two sites. That clears the t-test threshold of ten comfortably, and it is why the comparison between them holds up.
It does not clear thirty, which is what a standard error of the mean wants. Knowing that in advance would have meant either sampling more or planning to use a different statistic. It became an evaluation point instead, which is the second-best outcome.
Measure the conditions, not just the thing
The IB does not require this. It asks for data appropriate to your question and leaves the rest to you. We ask for it anyway, and the reason is worth understanding rather than just complying with.
Measure only your organisms and you can report that two places differ. Measure the conditions as well and you can explain why they differ, which turns a correlation into a mechanism.
That mechanism is also the bridge back to step 3. A strategy acts on conditions: clearing, draining, grazing, building. If you have measured the conditions, you can say what the strategy would do. If you have not, your fieldwork and your argument sit side by side and never touch.
What is living there, and how much of it
The conditions that decide what can live there
Light was measured twice with a lux meter: 12,000 on the piste against 5,000 in the forest. Two readings, taken at different moments, under moving cloud.
Canopy cover measures the same underlying thing and does not change while you walk between plots. Fifteen readings per site, one per quadrat, and suddenly it can be correlated against diversity rather than just quoted. Pick the stable version of what you are trying to capture.
Safety and ethics, about your investigation
No marks ride on a risk assessment any more, which has had an odd side effect: students either drop it entirely or paste in generic lab rules about tying back long hair. Neither helps.
What belongs here is what was actually risky about this work. Steep or uneven ground. Ticks. Working near water. Handling samples. And on the ethics side, what you did to leave the site as you found it, plus a consent form if people were involved.
Writing it in the future tense. "I will place five quadrats along each transect." It reads as a plan you might not have carried out, it hides everything you changed along the way, and it makes the account harder to trust. The fix takes ten minutes: go through and put the whole thing in the past tense, then add the two or three things that did not go as intended.
Ready for step 5?
0 of 10The first two are the criterion itself. The rest are how you get there.
Step 5 is where the good news arrives. Tables, graphs and calculations sit outside the word count entirely, so the six marks there cost you almost nothing to earn. Decide your statistical test now, before you go out, because it determines how much data you need to come back with.
The 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.