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Yeah, but no. It definitely is a buzzword that randomly gets attached to every method of data analysis these days. If you disagree, then please give me a defini
by Certhas 5y ago
Yeah, but no. It definitely is a buzzword that randomly gets attached to every method of data analysis these days. If you disagree, then please give me a definition that is both distinct from statistics but also means that Regression is an ML technique.
BTW, that doesn't mean there isn't also very substantial work done under the umbrella term.
Regression analysis was first introduced by Legendre in the early 19th century. I never would have dreamed to pretend it is Machine Learning 10 years ago when the term ML was still used somewhat more sparingly, and carried a bit more meaning...
But "I will use ML to analyse the data" gets more funding than "I will run a regression on the data".
- bonoboTP 5y agoI won't type up a chapter about this now but ML is about learning from data. It is concerned with training/validation/test data, the generalization error etc. Statisticians care more about "modeling", actually estimating parameters that stand in for something real, to check assumptions and hypotheses. The cultures are very different. What makes total sense to one may baffle the other as lunacy (there's more convergence now though, by realizing the complementary nature of the two approaches). The terminology is different too: in stats, they call logistic regression regression, while in ML it would have been called classification (but the name is now stuck). ML also tends to be more Bayesian than frequentist, as opposed to classical stats. I could write more but having taken ML courses before the big hype times, I can assure you ML doesn't just mean hyped up startup fluff vaporware. Open up Kevin Murphy's ML book and compare the TOC with a Statistics textbook. There is overlap but it's certainly different in its goals and mentality. It seems like some bitter bickering from the side of stats people that they didn't manage to hype up their field as much. Yeah they did have many of the same tools at their disposal but didn't use them in this way.
- 6gvONxR4sf7o 5y agoYou're setting up a strawman of statistics. You're describing a small part of a large field. Stats has been more than what you're describing for longer than ML has been a phrase. The only real useful definition these days is that stats is learning from data that happens in the stats department and ML is learning from data that happens in the CS department.
- bonoboTP 5y agoI'm fine with that. I would also hope for more collab cross-departments, but the incentives in academia are unfortunately not exactly set up the right way. People become protective of "their turf". I wrote a bit more here: https://news.ycombinator.com/item?id=26984234 https://news.ycombinator.com/item?id=26984234 I think it's good if people are aware of the origins of the methods they use. Regression wasn't invented under the umbrella of ML, but is analyzed from a particular angle in ML more than in stats.
- Certhas 5y agoI am a physicist by training. I have neither an applied math/stats nor a ML/comp sci background, but I am increasingly using these methods. So I am far from an expert, but I also am not coming at this from some start-up perspective. ML-the-buzzword is now penetrating into all parts of STEM research and research funding. Some of the potential applications are exciting, too. My conceptualization of the field is simply that ML is the design of universal function approximators to be used as part of statistical modeling/analysis. The key insight seems to be that a complex set of adapted network architectures, together with stochastic gradient descent are unreasonably effective. Further the effectiveness is a very non-linear function of size. As far as I can tell there is not much known about why this is the case. But as far as I can tell there really isn't anything done with these models that isn't statistical inference.
- nikk1 5y agoI agree ML is a buzzword and using a sentence like that would sound silly but I can elaborate. First, though, regression does not need a separate ML definition to make it distinct from statistics... there's tons of overlap in the field of mathematics. Machine learning is the study of computer algorithms that improve automatically through experience and by the use of data. This definition would include something as simple as linear regression. Linear regression attempts to model the relationship between two variables by fitting a linear equation to observed data. The purpose of a neural network is exactly the same as a line of best fit. That is, you are just approximating an unknown function based on input/output data. The only difference is that a NN can better approximate a nonlinear function.
- nonameiguess 5y agoThe generally accepted definition in the community is Tom Mitchell's: > A computer program is said to learn from experience E with respect to some task T and performance measure P, if its performance at task T, as measured by P, improves with experience E. Statistical estimation methods are one way to achieve this, but not the only way, especially when an exact function can be learned, i.e. a typical layer 2 switch is a learning device. You don't program in the mapping from connected device MAC addresses to switch port, the switch itself learns this from receiving a message from a MAC on a port and then records the mapping. That is a very simple form of non-statistical machine learning. I'm not really sure how you can start here but then say regression is not a form of machine learning. "Regression" is a pretty broad class of techniques that just means using labeled examples to estimate a function with a continuous response, typically contrasted with "classification," where the response is discrete. The method you use to do the function approximation may or may not be statistical. A genetic algorithm is not, for instance. I'm not sure least squares, which is what Legendre invented, should really be considered statistical, either. The original purpose was for approximating the solution to an overdetermined system of equations, before statistics was even formalized. It certainly became a preferred method in mathematical statistics, but mathematical statistics wasn't even formalized until later. It didn't start being called "regression" until Galton published his paper showing children of exceptionally tall or short people tended to regress to the mean, which was 80 years later. But you're performing regression analysis whether you use the normal equations, LU decomposition, QR decomposition, a genetic algorithm, gradient descent, stochastic gradient descent, stochastic gradient descent with dropout. Doesn't matter. As long as you're doing function approximation with a continuous response, it's still regression. Whether or not it can also be considered "machine" learning just depends on whether you're doing it by hand or via machine. Though sure, typically people tend to imagine the more exotic and newer techniques that scale to very large data sets and reduce overfitting and deal with noise automatically and involve hyperparameters, i.e. not least squares.