  The procedure used for structure function measurements at HERA is briefly
described and related to the properties of kinematic reconstruction. The
reconstruction methods of the inclusive deep inelastic scattering variables are
reviewed and their sensitivity to the energy and angle miscalibrations are
discussed in detail. New prescriptions are introduced and related to the
standard methods in order to optimize the F_2 structure function measurement
over the widest kinematic range, both in the low x, low Q^2 and in the high x,
high Q^2 regions. The prospects for the future high Q^2 studies are briefly
discussed.
