In practice, it may be more interesting to examine the degree to which the number of seats won by each party differs from that of a perfectly proportional outcome. In other words, how disproportional is the seat allocation. Unlike exact proportionality, disproportionality does not have a single unambiguous definition. Any index that takes the value of zero if the seat allocation is proportional and a larger value if it is not measures disproportionality. A number of such indexes has been proposed, including the Loosemore–Hanby index, the Gallagher Index, and the Sainte-Laguë Index.