  Within the framework of the relativistic plane wave impulse approximation, we
study the observable consequences of employing a complete Lorentz invariant
representation of the NN scattering matrix in terms of 44 independent
amplitudes, as opposed to the previously-employed, but ambiguous, five-term
Lorentz invariant parametrization of the NN scattering matrix, for the
prediction of complete sets of exclusive ($\vec{p},2 \vec{p} $) polarization
transfer observables. Two kinematic conditions are considered, namely proton
knockout from the $3s_{1/2}$ state of $^{208}$Pb at an incident energy of 202
MeV for coplanar scattering angles ($28.0^{\circ}, -54.6^{\circ}$), as well as
an incident energy of 392 MeV for the angle pair ($32.5^{\circ},
-80.0^{\circ}$). The results indicate that certain spin observables are ideal
for discriminating between the two representations.
