  Precise modeling of neutrino-nucleus scattering is becoming increasingly
important as accelerator-based oscillation experiments seek definitive answers
to open questions about neutrino properties. To guide the needed model
refinements, a growing number of experimental collaborations are pursuing a
wide-ranging program of neutrino interaction measurements at GeV energies. A
key step in most such analyses is cross-section extraction, in which measured
event counts are corrected for background contamination and imperfect detector
performance to yield cross-section results that are directly comparable to
theoretical predictions. In this paper, I review the major approaches to
cross-section extraction in the literature using representative examples from
the MINERvA, MicroBooNE, and T2K experiments. I then present two mathematical
techniques, blockwise unfolding and the conditional covariance background
constraint, which overcome some limitations of typical cross-section extraction
procedures.
