  We investigate how to experimentally detect a recently proposed measure to
quantify macroscopic quantum superpositions [Phys. Rev. Lett. 106, 220401
(2011)], namely, "macroscopic quantumness" $\mathcal{I}$. Schemes based on
overlap measurements for harmonic oscillator states and for qubit states are
extensively investigated. Effects of detection inefficiency and coarse-graining
are analyzed in order to assess feasibility of the schemes.
