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Okay, I offer you another analogy. Consider linear regression. Curve fitting. Taking a bunch of points (“data”) and trying to find a function (“algorithm”) tha
by cadamsdotcom 1y ago
Okay, I offer you another analogy.
Consider linear regression. Curve fitting. Taking a bunch of points (“data”) and trying to find a function (“algorithm”) that fits them all as closely as possible.
If the points form a straight line the process is fairly easy and can be done with a simple “y = Ax + B” equation. You just need to find A and B.
But if they look more spiky, bouncing up and down as you go across the x axis, fitting a curve to the data is going to require a higher order polynomial. A saddle, or U shape, can be fit with a second-order polynomial: “y = Ax^2 + Bx + C”, but if the data is more complex than this, you have to go even higher-order.
Now let’s move over to machine learning a language models. Consider the real-world data used to train models as points in some high-dimensional space, and the training process as iteratively performing curve-fitting in that same space. Some of your real-world data must certainly be easier to fit than others: even though it exists in a high order space, it could be fit to a curve with only a few parameters. In order words, in some domains the data appear “smoother” than others. For example have a look at machine learning’s success in image generation: varying a few pixels doesn’t affect the result too much. It’s a “smooth” domain.
But the same is not true everywhere. In math, or engineering - even grammar! - one symbol out of place makes the whole thing nonsense. These domains would be “spiky” - and some of them are minefields punctuated by islands of valid data, such they’re not even contiguous.
In spiky or non-contiguous domains, approximation won’t cut it. You have to fit your data REALLY closely to have a useful function - a useful model.
Models with more parameters are better equipped for curve fitting in complex domains with hard-to-fit data. So as we start to see multi-trillion-parameter models, maybe we’ll discover those models can handle complex domains today’s models can’t!
(keen readers may notice the risk of fitting the points exactly by having as many data points as the order of the polynomial. But actually this would be a triumphant achievement as at this scale we just don’t know what magical things lie on the curve, right there between the data points we have.)
- jraph 1y agoI'm quite convinced by this argument for ML / deep learning.