  We study the accuracy to be obtained in measuring trilinear $Z^0W^+W^-$ and
$\gamma W^+W^-$ couplings in the reaction $e^+e^- \to W^+W^-$ at "New Linear
Collider" energies of $500GeV$ to $1000GeV$. We derive simple scaling laws for
the sensitivity in the measurement of these couplings. For most couplings the
sensitivity increases as $\sqrt{L\cdot s}$, where $L$ denotes the integrated
luminosity and $\sqrt s$ denotes the $e^+e^-$ center-of-mass energy. Detailed
investigations based on various fits confirm these scaling laws and show that
an accuracy of the order of the standard radiative corrections can be reached
at the NLC for the design values of the luminosity.
