The Discriminatory Power (D)
is the average probability that the typing system will assign a different type to two
unrelated strains randomly sampled in the microbial population of a given taxon.
This tool has been created to help calculate this parameter, and source code is available at biophp.org 
Reference
Hunter P. Reproducibility and indices of discriminatory power of microbial typing methods. J Clin Microbiol 1990; 28: 19035. PubMed. A Discriminatory Power (D) value of 1.0 would indicate that a typing method was able to distinguish each member of a strain population from all other members of that population. Conversely, an index of 0.0 would indicate that all members of a strain population were of an identical type. An index of 0.50 would mean that if one strain was chosen at random from a strain population, then there would be a 50% probability that the next strain chosen at random would be indistinguishable from the first.
