Developing a Primary Sampling Program
Sampling programs delineate the sampling universe, sampling technique, sample unit size, number of sample units, pattern of collecting sample units, and timing of samples. An essential step in the development of a primary sampling program is the comparison and evaluation of potential sampling techniques. After selecting a sample unit and sampling technique, the next step in developing a sampling program is determining the pattern and timing of sampling and the optimal number of sample units. Some randomness can be introduced by collecting sample units at a randomly selected interval within the predetermined pattern on each sample date. Stratification of the habitat and randomly collecting sample units within strata is referred to as stratified random sampling. Stratifying into quadrats per field and plots per quadrat accounted for a very small proportion of the total variance; consequently, stratification of sample units was not recommended.