You produce a non-parametric distribution. Then you obtain, say, 10 random variables (RV) from this non-parametric distribution- much the same way as you would obtain random variables from a (parametric) normal distribution with stated mean and variance. But unlike the parametric distribution, where our RVs would occur around the mean (our parameter), RVs from a non-parametric distribution occur within the range bound by the lowest and highest mass point. This was not necessarily an intuitive concept to me, when I first stumbled across it. Which is why this mathematical proof of this range made me feel so much more comfortable:
If our estimate of the RV is a simple weighted-mean of the mass points:
Furthermore, since for RV
:
Since , we can express the inequality as:
On the other hand, If we know further information, like individual weights:
Furthermore, since for intercept :
Since , we can express the inequality as:
Thus, it is proven that any estimates of an RV drawn from a non-parametric distribution will be bound by the highest and lowest mass point.
Abbas Keshvani