1. Aims, Hypotheses & the Null Hypothesis
Why you can't just "go and measure the coast"
Imagine someone asks you to "study a river." That's impossible to actually do — a river might be hundreds of kilometres long, with a delta, floodplain, source and mouth. You'd need to pick ONE specific question about ONE specific stretch. Coasts work exactly the same way. That's why every piece of coastal fieldwork starts with a tightly focused aim.
Aim vs. Hypothesis — what's the actual difference?
These two get mixed up constantly, so let's separate them clearly:
- An aim is a purpose — what you're trying to find out. It often starts with "To investigate..." or "To explore...". Example: "To investigate how wave energy along X beach changes beach morphology."
- A hypothesis is a statement you can test and either support or reject with evidence. Example: "Coastal management strategies used at beach Y have taken conflicting views into account."
Think of the aim as the destination on a map, and the hypothesis as the specific claim you're checking is true along the way.
The null hypothesis — the most misunderstood idea here
This one trips a lot of students up, so let's build it from scratch. A null hypothesis is simply the opposite of your hypothesis. If your hypothesis says something IS happening, the null hypothesis says it is NOT happening.
Why bother with this at all? Because it protects you from bias. If you go out into the field already convinced your hypothesis is true, you might unconsciously only record evidence that supports it, and ignore evidence that doesn't. By setting up a null hypothesis alongside it, you force yourself to test both possibilities fairly. Whichever one the evidence actually supports — that's the one you accept. If you can't prove your original hypothesis, the null hypothesis must be true instead.
Worked Pattern
Hypothesis: "Coastal management strategies used at beach Y have taken conflicting views into account."
Null hypothesis: "Coastal management strategies used at beach Y have not taken conflicting views into account."
After the aim and hypothesis are set
Four things happen next, in this order:
- Select the sites (this involves sampling — see Topic 3)
- Decide on the equipment to be used
- Consider health and safety — complete a risk assessment
- Decide on data collection methods
Memory hook
Aim = the question. Hypothesis = the claim. Null hypothesis = the claim's opposite, there to stop bias.
Q1. Suggest one possible aim of a coastal environment investigation. (2 marks)
Q2. Identify three reasons why a coastal environment investigation may not achieve its aim. (3 marks)