Paired Samples

Two samples are said to be paired when each data point of the first sample is matched and is related to a unique data point of the second sample. For example consider the following study on the physiology of wheat maturation. Suppose an agronomist selected six wheat plants at random from a field plot. For each plant, she measured the moisture content in two batches of seeds: one batch from the "central" portion of the wheat head, and one batch from the "top" portion. Thus the seeds in each group are pairs, each pair from the same plant.

-- ErinEsp - 22 Feb 2010