Formulate a geographical question and hypothesis and choose an appropriate sampling method for fieldwork

What this dot point is asking

SEAB wants you to plan a geographical investigation: to write a focused question and a testable hypothesis, to know the stages an inquiry moves through, and to choose a sensible sampling method for collecting data. The central insight is that good fieldwork begins long before you leave the classroom; a sharp question and a sound sampling plan are what make the data you collect meaningful and the conclusion trustworthy.

The answer

A focused question and a testable hypothesis

An investigation starts with a geographical question: a clear, answerable question tied to a place and a variable, such as "Does the temperature in a park differ from the temperature on a nearby road?"

From the question you write a hypothesis: a testable statement of what you expect to find, for example "The road is warmer than the park." A good hypothesis:

• States an expected relationship or difference (not just a topic).
• Can be tested by collecting data.
• Can be supported or rejected by the evidence.

The hypothesis gives the whole investigation a focus, so you know exactly what data to collect.

The stages of an investigation

A geographical investigation moves through clear stages:

1. Ask a focused question and write a hypothesis.
2. Plan the methods: what data to collect, where, when and how to sample.
3. Collect primary and secondary data in the field.
4. Present the data with suitable maps, graphs and tables.
5. Analyse the data: describe and explain the patterns.
6. Conclude: decide whether the evidence supports or rejects the hypothesis, and evaluate the method.

Choosing a sampling method

You usually cannot measure everywhere or everyone, so you sample a manageable part. Three main methods:

• Random sampling: every point or person has an equal chance of selection (using random numbers or grid coordinates). It is unbiased but may by chance miss parts of the area.
• Systematic sampling: select at fixed, regular intervals (every $50\ \text{m}$ along a transect, every tenth person). It gives an even spread, ideal for studying change along a line.
• Stratified sampling: divide the population or area into groups (strata) and sample each in proportion to its size, so small but important groups are fairly represented.

Match the method to the aim: systematic for change with distance, stratified when there are distinct sub-groups, random when you want no pattern at all.

Examples in context

Example 1. A microclimate study in a Singapore neighbourhood. Students investigating the urban heat-island effect might hypothesise that temperatures are higher in a built-up HDB town centre than in a nearby park. They use systematic sampling, taking temperature readings every $100\ \text{m}$ along a transect from the park to the town centre at the same time of day. Plotting temperature against distance lets them test whether the built-up area is warmer, showing how a sharp hypothesis and systematic sampling produce data that answers the question.

Example 2. A river study using systematic sampling. A class studying how a stream changes downstream sets up survey sites at regular intervals along its course, measuring width, depth and speed at each. Systematic sampling along the stream ensures an even spread of sites from source to mouth, so the downstream changes are captured fairly. The same logic, fixed intervals along a line, is the standard plan whenever an investigation asks how something changes with distance.

Try this

Q1. Write a testable hypothesis for an investigation into whether a town centre is noisier than a residential area. [2 marks]

• Cue. A statement of expected difference that data can test, for example "Noise levels are higher in the town centre than in the residential area," which readings of noise can support or reject.

Q2. Name the sampling method that selects points at fixed, regular intervals, and give one situation where it is suitable. [2 marks]

• Cue. Systematic sampling; it is suitable for studying how something changes along a line or transect, such as measuring temperature every $100\ \text{m}$ from a park to a town centre.

Q3. Explain why a hypothesis helps to focus a geographical investigation. [2 marks]

• Cue. A hypothesis states exactly what relationship or difference is expected, so it tells the investigator precisely what data to collect and gives a clear yardstick at the end to decide whether the evidence supports or rejects the prediction.