A student is investigating soil infiltration rates in a public park to assess surface runoff risk. They used a homemade infiltrometer constructed from a cut-down plastic bottle to measure the time taken for 500 ml of water to drain into the ground. They took a single measurement at the center of three different grass playing fields at 8:00 AM on a hot, dry morning in August.
Suggest two ways that this data collection method could be adapted to make the data more reliable.
