You possibly can’t all the time get what you need
Generally, we don’t get what we wish. And typically, there are legal guidelines of nature that positively forbid us from getting it, regardless of how arduous we attempt.
The Cramér–Rao sure is one such regulation that fixes an indestructible glass ceiling — a tough higher sure — on the predictive precision achieved by any regression mannequin that anybody can consider.
On this article, we’ll research this regulation.
I’ll cowl the next two matters:
- WHAT is the Cramér–Rao Sure? I’ll introduce each the variance and the precision types of the sure. Piece-by-piece, I’ll unpack its definition, and I’ll clarify the way it all comes collectively.
- HOW is the Cramér–Rao Sure utilized to regression fashions? Utilizing an actual life dataset and a linear regression mannequin, we’ll research the applicability of the Cramér–Rao Sure to regression modeling.
The Cramér–Rao Sure (CRB) could be said in two methods: as a decrease sure on variance, and as an higher sure on precision.
If you learn it for the primary time, the definition of the Cramér–Rao Sure may really feel like you might be consuming from a hose. However don’t fear…