Читать книгу Laboratory Methods for Soil Health Analysis, Volume 2 - Группа авторов - Страница 26

The simple random sampling design assumes each given area has an equal opportunity of being selected (Table 2.3), and this typically involves pre‐selection of sampling points to avoid evaluator bias (Dick et al., 1996). Point selection may be done using a random number table and a coordinate grid overlain on an image of the sampling area, or with a random point generator and GIS (geographic information systems) software package (e.g., ArcGIS). Use of this sampling design minimizes bias associated with point selection.

Though easy to apply, simple random sampling has notable caveats since all points in an area are assumed to have equal importance, regardless of variation in inherent features and/or spatial stratification of management attributes. Spatial distribution of selected points therefore may not adequately represent an entire site, although this concern diminishes as the number of sample points increases. This design may be appropriate when knowledge of the site is limited.