  We compare two phenomenological models of dephasing that are in use recently.
We show that the stochastic absorption model leads to reasonable dephasing in
series (double barrier) and parallel (ring) quantum resistors in presence and
absence of magnetic flux. For large enough dephasing it leads to Ohm's law. On
the other hand a random phase based statistical model that uses averaging over
Gaussian random-phases, picked up by the propagators, leads to several
inconsistencies. This can be attributed to the failure of this model to dephase
interference between complementary electron waves each following time-reversed
path of the other.
