Normalizing open-closed string amplitudes

It has become increasingly clear that String Field Theory gives a complete definition of perturbative string theory, in addition to non-perturbative information.  I will discuss how to use open-closed string field theory to determine the normalization and sign of general amplitudes with both open and closed external states.  The challenges with signs arise because the relevant moduli spaces are not complex manifolds.  The normalization of amplitudes is controlled by the genus, the number of boundaries, the string coupling and the D-brane tension.