  Results of the recently developed unitary isobar model (MAID) are presented
for the spin asymmetries, structure functions and relevant sum rules in the
resonance region. The model describes the presently available data for
single-pion photo- and electroproduction in the resonance region below Wcm = 2
GeV very well. It is based on Born terms and resonance contributions, and the
respective multipoles are constructed in a gauge-invariant and unitary way for
each partial wave. The eta production is included in a similar way, while the
contribution of more-pion and higher channels is modeled by comparison with the
total cross sections and simple phenomenological assumptions. Our evaluation of
the energy-weighted integrals is in good agreement for the proton but shows big
discrepancies for the neutron.
