With iodide, the solvate $\ce{NaI \cdot 3(CH3)2CO}$ can be formed, in which each $\ce{Na+}$ is coordinated by 6 acetone ligands via oxygen lone pairs, and the $\ce{I-}$ ions fill in the gaps between these octahedral units, being surrounded by the methyl groups of the acetones.
Randomization is a sampling method used in scientific experiments. It is commonly used in randomized controlled trials in experimental research.
random. adj. 1. lacking any definite plan or prearranged order; haphazard: a random selection. 2. (Statistics) statistics. a. having a value which cannot be determined but only described probabilistically: a random variable. b. chosen without regard to any characteristics of the individual members of the population so that each has an equal chance of being selected: random sampling. 3. (of a person) unknown: some random guy waiting for a bus.