Abstract
Power of detecting inbreeding coefficient through a phenotype or mating type bioassay is evaluated as a function of sample size and level of inbreeding. Efficiency of a mating bioassay over a phenotypic one is then defined as the ratio of the two power functions for a given sample size while surveying the same population (i.e., with the same F). Empirical analysis of this efficiency function indicates that efficiency depends largely on n and F apart from the gene frequencies at the locus.