A group of islands are separated from each other by large stretches of water - HSC - SSCE Biology - Question 10 - 2019 - Paper 1

A suitable design feature for the investigation could involve selecting a control group that does not implement any quarantine measures. This would allow for a comparative analysis between the various quarantine policies implemented on the islands and the health outcomes in both the affected cattle population and the control group.

Additionally, data collection should be systematic, employing measures such as tracking disease incidence over time and monitoring cattle health across islands with differing policies. Random sampling could also enhance the validity of the results, ensuring that the findings are not biased by specific external factors affecting any single island. This design feature ultimately aims for robustness and reliability in assessing the effectiveness of each quarantine policy.