Figure 1: Different experiments can be used to test nonlocality. In each case, a source $S$ distributes the two parts of an entangled state $ρAB$ to two measuring devices. The measuring devices are provided with instructions on what measurement to perform. The measuring device then provides a classical output, symbolized here by which light bulb—green or red—lights up. (a) In the standard Bell scenario, the instructions to the measurement devices are classical [3]. The state exhibits nonlocality if the correlations between measurement settings and measurement results violate a Bell inequality. (b) In the scenario considered by Masanes, Liang, and Doherty [8], the instructions are classical, as in the standard Bell scenario, but the measurement apparatuses have access to an auxiliary entangled state $σAB$. This scenario enables the “activation” of hidden nonlocality. (c) In the semiquantum scenario introduced by Buscemi [4], the instructions $i$ and $j$ fed to the detectors are encoded in quantum systems described by quantum states $σAi$ and $σBj$. Appropriate choice of the states $σAi$ and $σBj$ can produce nonlocal correlations for all entangled states $ρAB$.