Ground rules are guidelines developed to minimize the subjectivity of sampling. Ground rules should be developed before field work commences, and should be clearly included in the sampling protocol. Ground rules are especially important to maintain sampling accuracy and precision when a number of different people are involved in data collection, or when data is collected over a number of years.
References and Further Reading
Greig-Smith, P. 1983. Quantitative plant ecology. Blackwell Scientific Publications, Oxford.3rd ed. pp 25-26.