Models of the Universe like the Concordance Model today used to interpret cosmological observations give expectation values for many cosmological observable so accurate that frequently peoples speak of Precision Cosmology. The quoted accuracies howev
er do not include the effects of priors used in optimizing the Model nor allow to evaluate the confidence one can attach to the Model. We suggest an estimator of the Confidence Level for Models and the accuracies of the expectation values of the Model observables
