Several methods have been devised for measuring the weak phase gamma using
decays of the type B-->DK. It is shown that these and other direct CP-viola
tion measurements suffer from discrete ambiguity which is at least 8-fold.
Combining two measurement methods helps reduce-the ambiguity and the experi
mental error. The measurement sensitivity and new physics discovery potenti
al are estimated using a full Monte Carlo detector simulation with realisti
c background estimates, giving particular consideration to ambiguities. [S0
556-2821(99)03117-3].