ELI5: Explain Like I'm 5

Backus–Gilbert method

The Backus-Gilbert method is a way to understand what's inside something even when we can't see it directly. It's like when we watch a magic show and the magician makes a coin disappear. We can't see where the coin went, but we can use other tricks to figure it out.

In the Backus-Gilbert method, we want to understand what's inside something called a function. A function is like a secret recipe that takes in some ingredients and tells us what the result will be. But sometimes, we can't figure out the recipe just by looking at the result. That's where the Backus-Gilbert method comes in.

The first thing we do is gather some information about the function. It's like asking the magician questions about the coin before it disappeared. We want to know how the function behaves in different situations. For example, if we give the function a small number, does it give us a small result? Or if we give it a big number, does it give us a big result?

Once we have enough information, we use a special formula to figure out what the secret recipe might be. It's like guessing how the magician made the coin disappear based on the tricks we've seen before. The formula takes into account all the information we gathered about the function and gives us a list of possible recipes.

But we're not done yet! We still need to figure out which recipe is the real one. This is like watching the magician closely to see where the coin went. We test each recipe to see if it matches up with what we know about the function. If it does, then we've found the magic recipe that describes how the function works!

So, in summary, the Backus-Gilbert method is a way of figuring out the secret recipe inside a function by gathering information, using a special formula to guess the recipe, and testing it to see if it works.