Practical Work, Field Study and Project Records
Practical work tests whether a candidate can plan a small field study, collect reliable data, present it and interpret it. The project record should show a clear question, method, observations, calculations and a reasoned conclusion.
Core rules and concepts
- A field study begins with an aim or hypothesis, followed by site selection, sampling method, instrument choice, data sheet design and safety planning.
- Sampling may be random, systematic or stratified. A transect is useful for studying change across a slope, stream bank or land-use boundary. A questionnaire must use clear, neutral and closed or coded questions.
- Record the date, time, location, weather, instrument number and observer. Tabulate raw data before calculating means, percentages or rates. Graphs must have titles and labelled axes with units.
- Common instruments include tape, clinometer, prismatic compass, soil auger, thermometer, rain gauge and float for stream velocity.
Worked example
A float travels 10 m downstream in 20 s. Surface velocity = distance ÷ time = 10 ÷ 20 = 0.5 m/s. Because surface flow is faster than the mean, apply a rough correction factor of 0.85: mean velocity ≈ 0.5 × 0.85 = 0.425 m/s. State the assumption and repeat runs to reduce error.
Traps that cost marks
- Mixing metres and centimetres in one calculation.
- Reporting a single reading as if it were representative.
- Omitting units, date, location or instrument details.
- Choosing a convenient sample that biases the result.
- Presenting a graph without a title or labelled axes.