  Most of the chemical evolution models are not very reliable for the last
5~Gyr of galactic evolution; this is mainly because abundance gradients found
in the literature show a big dispersion for young objects; a big culprit of
this is the dispersion found in HII region gradients. Part of this dispersion
arises from two different methods used to determine O/H in HII regions: the
direct method (DM), based on forbidden lines; and the temperature independent
method (TIM), based on permitted lines; the differences between these two
methods are about 0.25~dex. We present two chemical evolution models of our
galaxy to fit the O/H gradients of HII regions, one obtained from the DM and
the other obtained from the TIM. We find that the model based on the TIM
produces an excellent fit to the observational stellar constraints (B-stars,
Cepheids, and the Sun), while the model based on the DM fails to reproduce
them. Moreover the TIM model reproduces the flattening observed in the 3-6 kpc
galactocentric range; this flattening is attained with an inside-out star
formation quenching in the inner disk starting ~ 9 Gyr ago.
