A technique of assigning subjects to intervention and control groups that is based only on chance distribution. It is used to diminish selection bias.
In general, any factor that distorts the true nature of an event or observation. In clinical observations, a bias is any systematic factor other than the intervention of interest that affects the magnitude of an observed difference (i.e. trends to increase or decrease) in the outcomes of a treatment group and control group. Bias diminishes the accuracy (though not necessarily the precision) of an observation. Randomization is a technique used to decrease this form of bias. Bias also refers to a prejudiced or partial viewpoint that would affect someone’s interpretation of a problem. Double-blinding is a technique used to decrease this type of bias. See “blinding”.... bias
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