[en] We investigate the prospects of measuring anomalous couplings between gauge bosons at electron-positron-colliders with optimal observables. Such observables are shown to contain all information on the coupling parameters that can be extracted in a given reaction. Their sensitivity to the form factors in the general expressions of the triple gauge vertices WWZ and WWγ, including CP violating terms and absorptive parts, is calculated in view of LEP2 and the NLC. (orig.)