Core Unit 3: Geographical Investigation and Skills
Core Unit 3 combines your Geographical Investigation report, which carries 20% of the subject marks, with the map, graph and data skills tested in the written paper. The exam checks that you can design a fair investigation, handle data correctly and evaluate your own results.
Rules that decide marks
- Report structure: title, aim(s)/hypothesis, location and justification, methodology, data collection, results, analysis, conclusion, evaluation. Each section must be visible.
- Sampling: random, systematic (along a transect or at fixed intervals), or stratified. Name the method and justify it.
- Map skills: 4-figure grid references locate a square, 6-figure references locate a point. At 1:50,000, 1 cm on the map equals 500 m on the ground.
- Calculations: gradient = rise ÷ run; density = number ÷ area; discharge = cross-sectional area × velocity.
- Validity and reliability: sample size, repeats, equipment error, observer bias, weather conditions.
Worked example
A stream has a width of 4 m, mean depth of 0.5 m and mean velocity of 0.8 m/s. Calculate its discharge. Reasoning: cross-sectional area = 4 × 0.5 = 2 m². Discharge = 2 m² × 0.8 m/s = 1.6 m³/s (cumecs). State the unit - an answer without cumecs loses the interpretation mark, and a single measurement at one point is not representative of the whole channel.
Traps that cost marks
- Writing a methodology that reads like a recipe with no justification.
- Presenting results with no analysis of trend or anomaly.
- Forgetting to evaluate limitations and suggest improvements.
- Mixing up scale conversions or losing the units in calculations.