283 karma · joined June 27, 2019
https://www.linkedin.com/in/colin-vandenhof-6461b4119/
That said, it's common to use large models to generate synthetic training data for training other smaller models. In this way, we're able to transfer knowledge from one model to another.
The issue here is one of calibration: https://en.m.wikipedia.org/wiki/Calibration_(statistics). That is, the output probabilities of the neural network do not reflect the true (observed) probabilities. If it is systematically underestimating the probabilities, it is termed "underconfident", and if overestimating the probabilities, "overconfident".
Note that in these cases, it may still be improving as a classifier on unseen data, while still showing higher validation loss as calibration degrades.
What they demonstrate is a neural network learning an algorithm that approximates modular addition. The exact workings of this algorithm is explained in the footnotes. The learned algorithm is general -- it is just as valid on unseen inputs as seen inputs.
There's no memorization going on in this case. It's actually approximating the process used to generate the data, which just isn't possible using k nearest neighbors.
What the author is talking about here seems to be how to recognize and avoid confirmation bias.
The intuition for why this happens is that the losses of the majority are made up by the big gains of a minority. You can even see that after two iterations:
Case 1: two heads -- 225% wealth Case 2: heads, tails -- 90% wealth Case 3: tails, heads -- 90% wealth Case 4: two tails -- 36% wealth
So, most people are losing money but a single lucky guy makes enough money that the expected value is still positive.
If you run a simulation with a low sample size, you might not see this effect because the "lucky guy" case is rare (and gets more rare with more iterations).