After hearing about creating and implementing a model… what is a machine learning model really and how does it actually work?

Question

After hearing about creating and implementing a model… what is a machine learning model really and how does it actually work?

In: Technology

Answer 1

Machine learning is just a mathematical equation with a lot of inputs.

The best Eli5 way I can illustrate is to imagine a radio. You can tune the radio to some station. As you get closer you can tell you’re almost there by how clearly the sound comes in. As you get closer you slow down until you reach the maximum clarity.

Machine learning is much the same. Except instead of 1 dial you have thousands, if not millions. But the premise is the same. We have some idea of what the output should look like. So what we do is put in the inputs and see what the static sounds like, the output. We then run an analysis based on what we want the output to be. This is averaged over the thousands of training data sets we give it. This tells us by how much we need to tune our radio.

The averaging works so that the further away you are, the greater the change will be. But then as you get closer you tune the radio slower, so you get more precise.

A machine learning model is set up like this.

Input -> x (weight) -> (sum of all inputs times their weights) x (another weight) -> output

Each connection is a weight, and each node sums the weighted inputs and then multiplies it by a weight. Then it uses this new number as the new input.

Every weight is a dial we can use to tune the radio. So it gets pretty complex pretty fast. As far as what it is actually doing, we don’t know. You can guess that maybe it’s looking at specific features of a picture or maybe it’s analyzing some pattern on a chess board, but then at the same time you can feed static into a handwritting ML and it will confidently tell you that it’s a 5. So we ultimately aren’t sure why it works.

The point is that it is just a mathematical function. It’s like a radio, except it has a million dials. If you can find the radio station you’re looking for, whether thats playing chess or telling you if that picture is a cat or a dog, then you’ve created an effective machine learning algorithm.