2.5 Gy Theory and the Source of Sampling Error

Much has been written about sampling over the years; however, the sampling theory of Pierre Gy may be the most comprehensive and mathematically developed. Pierre Gy formed his theory for the sampling of particulate materials beginning in the 1950s, originally focused on the mining and mineral exploration industries, culminating in his final theory in the late 1980s and early 1990s (Gy 1998). Pitard (1993) summarized Gy's sampling theory for the English-speaking audience and extended it to environmental applications. While all of Gy theory applies to environmental sampling, this section focuses on minimizing sampling errors during extraction of samples from a parent matrix.