Quadrat technique used to sample the pop of species.
Sample: Random (Bias)
How they organize: Grid system. This enables you to identity all material - Works like a graph using coordinates. The guadrats are placed in the grid in individual squares - for placement for "Bias" sampling, you use "random" numbers and they are generated along the "x" & "y" axis.
Representative sampling : A small quantity of materials, whose characteristics represent (as accurately as possible) the entire batch,population.