  The mechanism of electroweak symmetry breaking in Little Higgs Models is
analyzed in an effective field theory approach. This enables us to identify
observable effects irrespective of the specific structure and content of the
heavy degrees of freedom. We parameterize these effects in a common operator
basis and present the complete set of anomalous contributions to gauge-boson,
Higgs, and fermion couplings. If the hypercharge assignments of the model
retain their standard form, electroweak precision data are affected only via
the S and T parameters and by contact interactions. As a proof of principle, we
apply this formalism to the minimal model and consider the current constraints
on the parameter space. Finally, we show how the interplay of measurements at
LHC and a Linear Collider could reveal the structure of these models.
