Bio-Env vs BVStep

BEST amalgamated the earlier (PRIMER 5) BIOENV and BVSTEP procedures (hence BEST = Bio-Env + Stepwise) since they had an identical purpose – to search for high matrix correlations, rank-based, between a fixed sample similarity matrix (typically from a species assemblage) and resemblance matrices generated from different variable subsets of a supplied data matrix (usually a transformed and normalised suite of environmental variables presumed to include those ‘driving’ the assemblage structure). The only difference in operation is that BIOENV carries out a complete search of all possible combin¬ations of variables from the datasheet, whereas BVSTEP caters for the common situation in which there are too many variables to do an exhaustive search, and a forward-stepping and backward-eliminating stepwise procedure is necessary to arrive at a (possibly) optimal set. Within Analyse>BEST, the first choice is therefore of Method•BIOENV or Method•BVSTEP. (BVSTEP will be discussed in Section 14, where it becomes essential for use on biotic matrices).