A more rigorous definition takes into account the fact that "θ" is actually unknown, and thus the convergence in probability must take place for every possible value of this parameter. Suppose } is a family of distributions (the parametric model), and } is an infinite sample from the distribution "pθ". Let { "Tn"("Xθ") } be a sequence of estimators for some parameter "g"("θ"). Usually "Tn" will be based on the first "n" observations of a sample. Then this sequence {"Tn"} is said to be (weakly) consistent if