ELI5: Explain Like I'm 5

Shrinkage estimator

Okay, let's imagine you have a big bag of marbles, but you don't know how many marbles are inside the bag. You want to guess how many marbles there are, but you don't want to just guess randomly because that might not be accurate.

So, to make a more accurate guess, you can take a sample of marbles from the bag. Let's say you take out 10 marbles and count them. Based on that sample, you can estimate how many marbles are in the whole bag. But, this estimate might not be exactly right because you only looked at a small part of the bag.

That's where the shrinkage estimator comes in. It helps make your estimate more accurate by using information from both the sample you took and what you already know about the bag of marbles.

For example, if you know that most bags of marbles have around 100 marbles, you can use that information to adjust your estimate based on your sample. The shrinkage estimator "shrinks" your estimate closer to the average, which makes it more accurate.

So, in short, the shrinkage estimator helps make a more accurate prediction by combining information from a sample and what you already know about the population as a whole. It's like guessing how many marbles are in the bag with a little extra help to make your guess more accurate!