The Relation between Folk and Scientific Classification of Plants and Animals

Methods are developed for decomposing agreement between classifications into two components: inclusiveness, or the extent to which groups in one classification strictly include groups in the other; and consistency, or the extent to which one classification subdivides the same groups that the other does. The methods are used to compare folk classifications with scientific classifications of plants and animals. Folk generics, which constitute the most salient taxonomic rank in folk classifications, are about as inclusive as scientific genera and definitely more inclusive than scientific species. Consistency between the classifications is substantial and independent of rank across the ranks of species, genus, and family.