  The observation of scaling in processes in which a weakly interacting probe
delivers large momentum ${\bf q}$ to a many-body system simply reflects the
dominance of incoherent scattering off target constituents. While a suitably
defined scaling function may provide rich information on the internal dynamics
of the target, in general its extraction from the measured cross section
requires careful consideration of the nature of the interaction driving the
scattering process. The analysis of deep inelastic electron-proton scattering
in the target rest frame within standard many-body theory naturally leads to
the emergence of a scaling function that, unlike the commonly used structure
functions $F_1$ and $F_2$, can be directly identified with the intrinsic proton
response.
