  We study the impact of new open charm muoproduction data from COMPASS and
preliminary W production data from STAR on NNPDFpol1.0, the first unbiased set
of polarized parton distributions recently delivered by the NNPDF Collaboration
and based on inclusive Deep-Inelastic Scattering data only. The information
contained in the new data sets is incorporated in our Monte Carlo parton
determination via Bayesian reweighting, a method based on statistical inference
which avoids the need for a global refitting. We explicitly show to which
extent COMPASS and STAR data can improve our knowledge of gluon and antiquark
polarized parton distributions respectively.
