# Choosing which interest rate model to go with?

I've been assigned with the task of modelling zero rate curve. I did it with two models: Vasicek and CIR. Looking at the two curves produced, I can see that one is closer to the observed curve than the other, but I am asked to perform some quantitative tests to confirm this observation. My question is this: Do you know of any tests for such a thing ?

One more note, given a set of model parameters, you can generate curves at future times (formulas for zero-coupon bond prices, $$P(t,T)$$, are valid for all $$t\geq 0$$, not just $$t=0$$, and all $$T \geq t$$). This exercise (somewhat complementary to the calibration test) shows the capacity of the model to generate a reasonable variety of curve shapes at future times.