 Both the single-mind and many-minds theories can be thought of as hidden-variable theories like   Bohmian mechanics.  But instead of position being made determinate, as it is in Bohm’s theory, and then assuming that the determinate positions of particles will provide observers with determinate measurement records, it is the mental states of the observers that are directly made determinate here, and while this is a non-physical parameter, it is guaranteed to provide observers with determinate measurement records.