Generally, we don’t get what we wish. And generally, there are legal guidelines of nature that positively forbid us from getting it, irrespective of how arduous we strive.
The Cramér–Rao certain is one such regulation that fixes an indestructible glass ceiling — a tough higher certain — on the predictive precision achieved by any regression mannequin that anybody can consider.
On this article, we’ll examine this regulation.
I’ll cowl the next two subjects:
- WHAT is the Cramér–Rao Sure? I’ll introduce each the variance and the precision types of the certain. 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 examine the applicability of the Cramér–Rao Sure to regression modeling.
The Cramér–Rao Sure (CRB) could be acknowledged in two methods: as a decrease certain on variance, and as an higher certain on precision.
Whenever you learn it for the primary time, the definition of the Cramér–Rao Sure may really feel like you might be ingesting from a hose. However don’t fear…