Spatial Sampling

It is self-explanatory that whatever we sample must be representative of the object of study. However, for statistical purposes the simple random sample is essential and its desirability may at first seem like an obscure and unnecessary display of erudition. For example, when sampling soils, we might be able to randomly choose sites from almost any part of the study area. Unfortunately, differences in topography, land use, history of land use, microclimate, the current weather and time of day may all bias the selection of specimens drawn from the population.