Effective biological monitoring requires sampling techniques that efficiently and accurately enable researchers to assess status and trends of a biological resource. Sampling - the process of selecting a subset of units from a population of interest – can range from simple random sampling to complex sampling designs that might include nesting, stratification, clustering, or some combination thereof. In the case of simple random sampling, every element of the target population has an equal chance of being selected (uniform inclusion probability).
Well-designed sampling designs, when properly applied, can increase precision of population estimates and statistical power to detect population trends, especially when the mean or variance of an attribute varies significantly across a definable attribute.
South Fork Research specializes in generating survey designs for monitoring programs. Recent work includes a novel method for incorporating survey design weights into model-based estimates.