  The partial adiabatic search algorithm was introduced in [A. Tulsi, Phys.
Rev. A 80, 052328 (2009)] as a modification of the usual adiabatic algorithm
for quantum search with the idea that most of the interesting computation only
happens over a very short range of the adiabatic path. By focussing on that
restricted range, one can potentially gain advantage by reducing the control
requirements on the system, enabling a uniform rate of evolution. In this
comment, we point out an oversight in the original work [1] that invalidates
its proof. However, the argument can be corrected, and the calculations in [1]
are then sufficient to show that the scheme still works. Nevertheless,
subsequent works [2-6] cannot all be recovered in the same way.
