Graphical models illustrating the isolated models and the joint model approach.

<p>A graphical model illustrates the dependencies between the variables of a model. The plates in the background of both graphical models group variables according to condition <i>i</i>. In panel A, the observed variable , the data from condition <i>i</i>, depends on the random variables and , each being characteristic for condition <i>i</i>. The only difference in the second panel is that the random variable is outside the background plate, which means the variable does not depend on condition <i>i</i>—it is shared across conditions.