Geography

1. 1.

   Fictional fieldwork: infiltration times for a fixed water volume at five park sites are 20, 22, 25, 28, 55 seconds. Lower time means faster infiltration under this protocol. All readings are invented. Students used safe level ground but chose sites near a path for convenience; soil moisture was not recorded. Explain why fixed water volume is needed when comparing times.

   [2 marks] · no calculator

   Answer explanation

   Draft walkthroughs are based on marking guidance, not independently verified derivations.

   1. Holding volume constant removes one procedural source of variation. It does not automatically control soil condition, ring size or the pressure head.
   2. Award each point once. Accept other well-supported interpretations addressing the task.

   Marking points

   • Different volumes would change the amount required to infiltrate.
   • Standardising volume makes time comparisons more interpretable as differences between sites.

   Examiner tip: A fair comparison needs more controls than volume alone.

2. 2.

   Fictional fieldwork: infiltration times for a fixed water volume at five park sites are 20, 22, 25, 28, 55 seconds. Lower time means faster infiltration under this protocol. All readings are invented. Students used safe level ground but chose sites near a path for convenience; soil moisture was not recorded. Calculate the median and range of infiltration times.

   [2 marks]

   Answer explanation

   Draft walkthroughs are based on marking guidance, not independently verified derivations.

   1. The readings are already ordered. Select the third of five for the median and subtract the minimum from the maximum for the range; neither statistic is an infiltration velocity.
   2. Award each point once. Accept other well-supported interpretations addressing the task.

   Marking points

   • The ordered middle observation gives median = 25 seconds.
   • Range = 55 - 20 = 35 seconds.

   Examiner tip: Do not divide by time to claim a rate without volume and area information.

3. 3.

   Fictional fieldwork: infiltration times for a fixed water volume at five park sites are 20, 22, 25, 28, 55 seconds. Lower time means faster infiltration under this protocol. All readings are invented. Students used safe level ground but chose sites near a path for convenience; soil moisture was not recorded. Explain how path-side convenience sampling may bias the result.

   [3 marks] · no calculator

   Answer explanation

   Draft walkthroughs are based on marking guidance, not independently verified derivations.

   1. Site accessibility can correlate with the process being measured. A convenient sample therefore risks systematically selecting slower-infiltrating ground rather than the full park variation.
   2. Award each point once. Accept other well-supported interpretations addressing the task.

   Marking points

   • Path-side soil may be compacted by foot traffic.
   • Compaction can reduce pore space and slow infiltration.
   • The sample may underrepresent less disturbed parts of the park.

   Examiner tip: Bias is a systematic selection problem, not just a small sample size.

4. 4.

   Fictional fieldwork: infiltration times for a fixed water volume at five park sites are 20, 22, 25, 28, 55 seconds. Lower time means faster infiltration under this protocol. All readings are invented. Students used safe level ground but chose sites near a path for convenience; soil moisture was not recorded. Explain how to investigate the 55-second reading without simply deleting it.

   [3 marks] · no calculator

   Answer explanation

   Draft walkthroughs are based on marking guidance, not independently verified derivations.

   1. An unusual value can reveal genuine spatial heterogeneity. Verification distinguishes measurement error from an informative local condition; deletion requires an evidenced reason.
   2. Award each point once. Accept other well-supported interpretations addressing the task.

   Marking points

   • Check the recorded method and instrument setup for mistakes.
   • Repeat at and around the site to test whether slow infiltration persists.
   • Record soil and disturbance differences and retain a valid extreme result.

   Examiner tip: An outlying value is not automatically an erroneous value.

5. 5.

   Fictional fieldwork: infiltration times for a fixed water volume at five park sites are 20, 22, 25, 28, 55 seconds. Lower time means faster infiltration under this protocol. All readings are invented. Students used safe level ground but chose sites near a path for convenience; soil moisture was not recorded. Design a stronger test of whether trampling slows infiltration.

   [4 marks] · no calculator

   Answer explanation

   Draft walkthroughs are based on marking guidance, not independently verified derivations.

   1. A paired design compares similar soil under different trampling conditions. Replication and recorded covariates strengthen inference while avoiding a destructive experiment.
   2. Award each point once. Accept other well-supported interpretations addressing the task.

   Marking points

   • Samples matched trampled and less-trampled locations across multiple areas.
   • Controls volume, ring geometry and procedure across measurements.
   • Records soil moisture, texture and slope to assess confounding.
   • Repeats measurements and uses safe access and permission without deliberately damaging vegetation.

   Examiner tip: Match sites by relevant conditions, not merely by being nearby.

6. 6.

   Fictional fieldwork: infiltration times for a fixed water volume at five park sites are 20, 22, 25, 28, 55 seconds. Lower time means faster infiltration under this protocol. All readings are invented. Students used safe level ground but chose sites near a path for convenience; soil moisture was not recorded. Assess whether these five readings justify a park-wide drainage intervention.

   [4 marks] · no calculator

   Answer explanation

   Draft walkthroughs are based on marking guidance, not independently verified derivations.

   1. Measurement of infiltration is not proof of a damaging drainage problem. Establish where water accumulates and what consequences occur before altering hydrology across the park.
   2. Award each point once. Accept other well-supported interpretations addressing the task.

   Marking points

   • They indicate variation at the sampled sites, including one slow reading.
   • Convenience selection limits park-wide representativeness.
   • Rainfall, ponding, ecological effects and wider sampling are needed for a management decision.
   • Recommends investigation or targeted action rather than a conclusive park-wide prescription.

   Examiner tip: Distinguish a measured process from evidence that intervention is needed.

Original, unofficial practice questions from SubjectScout — not official past-paper questions.