Fieldwork skills — CCEA Unit 3

Unit 3 (20% of the GCSE) tests your fieldwork methodology and data skills in a written exam. You will have conducted two fieldwork enquiries (one physical, one human geography) during the course. In the exam you must be able to explain your methods, justify your choices, and evaluate the success of your enquiry.

Sampling strategies

It is rarely possible to collect data from every location or person. Sampling strategies select a manageable subset:

Random sampling: every location or individual has an equal chance of being selected. Removes bias. Disadvantage: may miss important features by chance.

Systematic sampling: data collected at regular intervals (every 5 metres, every 10th house). Efficient and easy to apply. Disadvantage: may coincide with a regular pattern in the data (e.g. every 10th house is a corner plot).

Stratified sampling: the population is divided into groups (strata) — e.g. age groups, land use types — and samples are taken from each in proportion to their size. Ensures all sub-groups are represented.

Stratified random sampling: combines the two — random selection within each stratum.

Pragmatic (opportunity) sampling: choosing accessible or convenient locations. Honest acknowledgement of time and access constraints. Recognised as less rigorous.

Data types

Primary data: collected directly by the student during fieldwork. E.g. river velocity measurements, land use mapping, questionnaire responses.

Secondary data: collected by others. E.g. Environment Agency river flow data, Census data, ordnance survey maps.

Quantitative data: numerical. E.g. river velocity (m/s), temperature (°C), number of pedestrians per 5 minutes.

Qualitative data: descriptive or observational. E.g. quality of pedestrian environment scored on a bi-polar scale, photographs, interview transcripts.

Presentation methods

Choose the presentation method that is most appropriate for your data type:

Data type	Suitable presentation
Changes along a transect	Line graph, cross-section diagram
Comparisons between categories	Bar chart, divided bar chart
Proportions of a whole	Pie chart
Spatial distribution	Choropleth map, dot map, isoline map
Correlation between two variables	Scatter graph
River cross-section	Annotated cross-section diagram

Statistical analysis

Mean: average of all values. Sensitive to extreme values (outliers).

Median: middle value when data is ranked. More reliable than mean when outliers are present.

Spearman's Rank Correlation Coefficient: tests the strength and direction of correlation between two sets of ranked data. Used in GCSE Geography when comparing, e.g., pebble size and distance from source. Result (rs) ranges from +1 (perfect positive) to -1 (perfect negative).

Evaluating fieldwork

Reliability: would the results be similar if the study was repeated? Issues: subjective judgements (bi-polar analysis), time of day, weather conditions, small sample size.

Validity: does the data actually measure what you intended to measure? Issues: indirect proxies may not capture the concept well.

Improvements: always suggest at least two specific, realistic improvements — more sample points, different time of day, larger questionnaire sample, GPS recording of exact locations.