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.
A randomized controlled trial (or randomized control trial; RCT) is a type of scientific (often medical) experiment, where the people being studied are randomly allocated one or other of the different treatments under study.The RCT is often considered the gold standard for a clinical trial. This type of randomization can be combined with stratified randomization, for example by center in a multicenter trial, to ensure good balance of participant characteristics in each group.. 2  A special case of permuted-block randomization is random allocation, in which the entire sample is treated as one block.