  A reanalysis of unpolarized electron-proton elastic scattering data is done
in terms of the electric to magnetic form factor squared ratio. This observable
is in principle more robust against experimental correlations and global
normalizations. The present analysis shows indeed that it is a useful quantity
that contains reliable and coherent information. The comparison with the ratio
extracted from the measurement of the longitudinal to transverse polarization
of the recoil proton in polarized electron-proton scattering shows that the
results are compatible within the experimental errors. Limits are set on the
kinematics where the physical information on the form factors can be safely
extracted. The results presented in this work bring a decisive piece of
information to the controversy on the deviation of the proton form factors from
the dipole dependence.
