  Numerous non-standard dynamics are described by contact-like effective
interactions that can manifest themselves through deviations of the cross
sections from the Standard Model predictions. If one such deviation were
observed, one should try to identify to a given confidence level the actual
source among the possible non-standard interactions that in principle can
explain it. We here estimate the potential identification reach on different
New Physics effective interactions, obtainable from the angular distributions
of lepton pair production processes at the planned International Linear
Collider with polarized beams. The models discussed are the interactions based
on gravity in large and in TeV^{-1} extra dimensions and the
compositeness-inspired four-fermion contact interactions. The availability of
both beams polarized in many cases plays an essential role in enhancing the
identification sensitivity.
