Are there reliable methods to estimate the nuclear orientation of
  Seyfert galaxies?
  Orientation, together with accretion and evolution, is one of the three main
drivers in the Grand Unification of Active Galactic Nuclei (AGN). Being
unresolved, determining the true inclination of those powerful sources is
always difficult and indirect, yet it remains a vital clue to apprehend the
numerous, panchromatic and complex spectroscopic features we detect. There are
only a hundred inclinations derived so far; in this context, can we be sure
that we measure the true orientation of AGN? To answer this question, four
methods to estimate the nuclear inclination of AGN are investigated and
compared to inclination-dependent observables (hydrogen column density, Balmer
linewidth, optical polarization, and flux ratios within the IR and relative to
X-rays). Among these orientation indicators, the method developed by Fisher,
Crenshaw, Kraemer et al., mapping and modeling the radial velocities of the [O
iii] emission region in AGN, is the most successful. The [O iii]-mapping
technique shows highly statistically significant correlations at >95%
confidence level for rejecting null hypothesis for all the test cases. Such
results confirm that the Unified Model is correct at a scale ranging from
kiloparsec to a fraction of a parsec. However, at a radial distance less than
0.01 pc from the central black hole, warps and misalignments may change this
picture.
