  We introduce a new phenomenological tool based on momentum region indicators
to guide the analysis and interpretation of semi-inclusive deep-inelastic
scattering measurements. The new tool, referred to as "affinity", is devised to
help visualize and quantify the proximity of any experimental kinematic bin to
a particular hadron production region, such as that associated with transverse
momentum dependent factorization. We apply the affinity estimator to existing
HERMES and COMPASS data and expected data from Jefferson Lab and the future
Electron-Ion Collider. We also provide an interactive notebook based on Machine
Learning for fast evaluation of affinity.
