  Microlensing event OGLE-2002-BLG-055 is characterized by a smooth, slightly
asymmetric single-lens curve with an isolated, secure data point that is ~0.6
magnitudes brighter than neighboring points separated by a few days. It was
previously suggested that the single deviant data point and global asymmetry
were best explained by a planetary companion to the primary lens with mass
ratio log(q)=-3 to -2, and parallax effects induced by the motion of the Earth.
We revisit the interpretation of OGLE-2002-BLG-055, and show that the data can
be explained by wide variety of models. We find that the deviant data point can
be fit by a large number of qualitatively different binary-lens models whose
mass ratios range, at the ~3-sigma level, from log(q) ~ -4 to -1. This range is
consistent with a planet, brown dwarf, or M-dwarf companion for reasonable
primary masses of M> 0.8 M_sun. A subset of these binary-lens fits consist of a
family of continuously degenerate models whose mass ratios differ by an
order-of-magnitude, but whose light curves differ by <2% for the majority of
the perturbation. The deviant data point can also explained by a binary
companion to the source with secondary/primary flux ratio of ~1%. This model
has the added appeal that the global asymmetry is naturally explained by the
acceleration of the primary induced by the secondary. The binary-source model
yields a measurement of the Einstein ring radius projected on source plane of
\hat r_E=1.87 +/- 0.40 AU. OGLE-2002-BLG-055 is an extreme example that
illustrates the difficulties and degeneracies inherent in the interpretation of
weakly perturbed and/or poorly sampled microlensing light curves.
