Evaluating Your Investigation — The Highest-Mark Stage
Part of Fieldwork Process and Enquiry — GCSE Geography
This deep dive covers Evaluating Your Investigation — The Highest-Mark Stage within Fieldwork Process and Enquiry for GCSE Geography. Revise Fieldwork Process and Enquiry in Fieldwork for GCSE Geography with 15 exam-style questions and 20 flashcards. This topic shows up very often in GCSE exams, so students should be able to explain it clearly, not just recognise the term. It is section 9 of 16 in this topic. Use this deep dive to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 9 of 16
Practice
15 questions
Recall
20 flashcards
⚖️ Evaluating Your Investigation — The Highest-Mark Stage
Evaluation is not listing everything that went wrong. It is a structured, critical assessment of the quality of the entire investigation — one that makes a reasoned judgment about how much confidence you can place in your conclusions. A strong evaluation addresses three distinct dimensions.
The Three Evaluation Dimensions
| Dimension | What It Asks | How to Improve It |
|---|---|---|
| Reliability | Would you get the same results if you repeated the investigation using the same method? Unreliable data varies due to random error, inconsistent technique, or changing conditions between measurements. | Take repeat measurements at each site and calculate the mean; use a larger sample size; standardise the method carefully (e.g., always measure velocity at 0.6 × channel depth); use the same equipment throughout; note and control for changing conditions |
| Validity | Does your data actually measure what your enquiry question requires? Data can be reliable (consistent) but invalid (measuring the wrong thing). For example, the float method measures surface velocity — but mean channel velocity at 0.6 × depth would be a more valid measure of overall flow. | Use multiple complementary methods (triangulation); cross-check primary data against secondary data; choose equipment specifically suited to the variable being measured; control confounding variables |
| Representativeness | Is your sample representative of the whole population or study area? A small sample, or one biased towards accessible or convenient locations, may not reflect the broader pattern. | Increase the sample size; use stratified sampling to ensure all sub-groups are represented; collect data at different times of day and different seasons; compare your sample characteristics against known population data |
Common Fieldwork Weaknesses and Specific Improvements
| Weakness | Why It Matters | Specific Improvement |
|---|---|---|
| Data collected on one day only | Weather, time of year, and unusual events can all affect results; results may not be representative of typical conditions | Collect data on three different days across different seasons; compare results and note any variation |
| Small sample size (e.g., 8 questionnaire respondents or 5 river sites) | Small samples are easily distorted by one or two unusual values; statistical tests become unreliable with fewer than 10 data pairs | Increase questionnaire sample to at least 30 per zone; increase river sites to 10+ to allow valid use of Spearman's rank |
| Only one data collection method used | A single method can only measure one dimension of the phenomenon; it cannot identify whether the pattern holds from multiple angles | Triangulate using a second method — e.g., supplement pedestrian counts with an environmental quality survey at the same sites |
| Personal subjectivity in bi-polar surveys or land use classification | Different observers may score the same location differently, reducing reliability | Use a structured recording sheet with clear criteria for each score; have two observers assess the same site independently and compare scores |
| Questionnaire carried out at one time of day (e.g., Tuesday morning only) | The sample will over-represent people available at that time — retired people, those not in work — and under-represent commuters and students | Repeat the questionnaire at different times (morning, lunchtime, evening) and on both weekdays and a weekend; stratify the sample by time slot |
| Float method for river velocity | Surface velocity is typically 20–25% faster than mean channel velocity; results overestimate true discharge | Use a flow meter at 0.6 × channel depth to measure mean velocity directly; or apply the standard correction factor (multiply surface velocity by 0.8) |