Randomization refers to the process whereby individuals are assigned to study groups without biases or differences resulting from selection.
A technique for assigning experimental
subjects to experimental and control groups randomly.
The use of a random process to help avoid a systematic relationship between two variables. The intent is to disrupt any systematic relationship that might exist between extraneous variables and the independent variable.
List of books: Randomization
Other /More definition:
randomization refers to method for placing individuals into research groups that assures each an equal chance of being assigned to any group, thus eliminating any systematic differences across groups.