1) Organisation 2) Organization 3) Randomization 1) Randomization 
The random assignment of subjects to experimental and control groups (i.e. the allocation to groups is determined by chance)
The allocation to a treatment group that is performed at random.
The process of ensuring that a sample is truly random. There are many ways of doing this, and to different levels. The entire sample should be chosen according to some strategy that does not unduly favour any particular group of individuals. A further level ensures that the subjects already chosen for the study are randomly allocated to the treatme...
<statistics> The process by which patients in a clinical trial are randomly assigned to different treatments Randomisation minimizes the differences among groups by equally distributing people with particular characteristics among all the trial arms. ... (09 Oct 1997) ... 
Process of putting into groups by chance, to make sure there is no bias.