  I first review a few basic guiding principles that lead to the notion of a
hierarchy of couplings in searches of New Physics involving weak bosons
processes. The hierarchies within a linear and a non-linear realization of
symmetry breaking are compared to the usual {\em phenomenological}
parameterization of the $WWV$ vertex. Limits that one expects to obtain at the
NLC(500GeV) and LHC/SSC on the tri-linear and quadri-linear anomalous $W$
couplings are compared. The cleanness of an \epm gives the NLC a clear
advantage in constraining the tri-linear couplings. However, with ``only"
$500$GeV, the \epm is not competitive with $pp$ colliders in probing the
quadri-linear couplings. An interpretation in terms of scalar-like and
vector-like models is given and I argue that in the presence of a light (or
``not-so-heavy") Higgs, the New Physics affecting the $W$ sector would be
easier to pin-down with a moderate energy \epm machine.
