# Independent Samples

Two samples are said to be independent when the data points in one sample are unrelated to the data points in the second sample. For example suppose we are interested in measuring the prothrombin time (a measure of the clotting ability of blood in seconds) for two groups of mice. To do this we randomly sample 10 mice to receive the treatment and 10 mice to be the control group. These two samples are taken independently of each other.
-- ErinEsp - 22 Feb 2010