Which question calls for a transect?
Consider the question: How does the type and intensity of pedestrian activity change with distance from a transit interchange along a fixed commercial street? A route-based design is plausible because distance is measurable and locations can be revisited. It would not establish why activity changes without supporting evidence or controls. A survey about residents' housing security, by contrast, might require a stratified or consent-based sampling design rather than evenly spaced street stops.
The IB's 2026 examiner instructions require locally scaled Geography fieldwork built on your own primary observations and measurements. Shared preparation and collection are allowed, but each student's analysis and written report must be their own. The report limit is 2,500 words. A transect is one possible method, not a universal requirement or a mark-winning formula.
Choose site spacing before you see the results
For a straight, safely accessible 600 m route with seven sites including both endpoints, the rule is 600 ÷ (7 − 1) = 100 m between sites. Precommitting to spacing reduces the temptation to take readings only where activity looks interesting. It does not remove bias from choosing the street, the start point or the observation time.
Site spacing: 100.00 m
Distances are measured along the route from the chosen starting point. This tool does not determine accessible locations, coordinates, representative sampling or safety.
- Site 10.00 m
- Site 2100.00 m
- Site 3200.00 m
- Site 4300.00 m
- Site 5400.00 m
- Site 6500.00 m
- Site 7600.00 m
An example fieldwork sheet, before measurements
The descriptions below are a fictional planning scenario. They are not observations, measured data or a place you can cite as having visited. At each site, a real student would record the exact location, date, time, ten-minute pedestrian count, a repeat, land-use observations, context, consent constraints and unexpected events. Do not write fictional values into an IA as collected evidence.
| Site | Distance | Hypothetical location | Fieldwork check |
|---|---|---|---|
| A | 0 m | Near station entrance | Heavy foot traffic; safe standing position needed |
| B | 100 m | Retail frontage | Customers may block the observation line |
| C | 200 m | Crossroad | Use designated pedestrian areas only |
| D | 300 m | Mixed frontage | One temporary closure can distort land-use counts |
| E | 400 m | Residential stretch | Private property is not a fieldwork site without permission |
| F | 500 m | Park edge | Compare shade, surface and observation conditions |
| G | 600 m | Route endpoint | Check that the final site is safely accessible |
Three biases your method cannot erase
Spatial selection: a single street may differ from others because of transit, topography or land use. Your conclusion should be about the selected corridor, not automatically the whole city.
Temporal variation: lunch-hour and evening counts are not directly interchangeable; record exact clock times and consider a second observation window. Do not pool unrelated windows without a justified design.
Observer and access effects: people may change their behaviour around visible observers and some planned stops may be unsafe or inaccessible. Record substitutions rather than silently treating them as original random or systematic sites.
How to write the method in a way someone can repeat
Describe the exact selected street with a map and coordinates, the safety and access checks, how distances were measured, the site spacing rule, the two timed counting windows, any other observed variables, and where raw measurements are stored. Distinguish what you planned from what actually happened. Explain why the collected data address your question. The examiner should be able to connect every map and statistic back to a site and observation, not merely trust a polished chart.
If 100 m spacing skipped two accessible high-use nodes, record that as a limitation. Consider showing both the systematic sample and an independently planned supplementary observation, clearly labelled. Do not retrospectively redefine your sample to make the result fit a preferred land-use theory.
After your fieldwork
Use Geography IA ideas for research-question alternatives or open Geography review when you have your own draft and evidence. Automated feedback is not an official assessment.
Sources & verification
Primary-source references used to verify key assessment facts on this page. Last source check: October 14, 2026.
This is an original fictitious design exercise, not a report of actual fieldwork, graded writing or IB-endorsed sampling procedure.
- IB 2026 Geography examiner instructionsPrimary authority for local primary-data fieldwork, 2,500-word report limit, moderation and original individual analysis.
- IB Geography subject briefOfficial Geography programme and SL/HL fieldwork context.
- Existing Geography IA topic directionsExisting canonical question and topic directions, distinct from this example of how to plan a sampling instrument.