text: The Wu theory provides more accurate results than do the other two component theories, particularly for high surface energies. It does, however, suffer from one complication: because of the mathematics involved, the Wu theory yields two results for each component, one being the true result, and one being simply a consequence of the mathematics. The challenge at this point lies in interpreting which is the true result. Sometimes this is as simple as eliminating the result that makes no physical sense (a negative surface energy) or the result that is clearly incorrect by virtue of being many orders of magnitude larger or smaller than it should be. Sometimes interpretation is more tricky.