Replicate Measurements

Replicate measurements come in two substantially different forms, depending on the circumstances under which they are taken: exchangeable and linked. Replicate measurements by a method on a given item are said to be exchangeable if there is no relationship between the first, second, etc. replicate across methods. When replicate measurements are available, the aim of the analysis is exactly the same as without replicates; derivation of a prediction interval for one method given the other, or, equivalently, derivation of a prediction interval for the difference. There are two basic ways of indicating in the plot how the replicates belong together within items, depending on whether replicates are linked or not. Controlled Vocabulary Terms replication