Consider the following generative model to explain how the data arise.

The following figure, theta 1 and theta 2 mean model parameters.

In the model, theta 2 does not effect the data.

To validate the model, one method is to replicate the data from a known parameter and show that the mean of estimates over replications and true parameter does not differ.

The following model, the second parameter theta 2 does not affect directory the generative process of data. So, we no need to assume the true parameter `theta 2`

to generate the replicated data.

So, lack of the true parameter `theta 2`

leads us the impossibility of comparison of estimates and true parameter ?