selected at random definition
selected at random usually means ‘‘selected at random with uniform probability’ ‘—i.e., sampling should insure that all units of the model should have the same chance of being selected to be tested. However, this is impossible if samples are selected for certification testing before production of the model has been discontinued. samples are selected after only a few units have been produced; consequently, the sampling procedure does not guarantee that the samples are representative of
selected at random means that the probability distribution for the normalized vector ψ2 is uniform on the (real) (2N 1)- sphere (this is the unique distribution that is invariant under arbitary unitary transformations). Note that, for fixed θ, eiϕ