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Reminds me of this horrifying stack exchange post: https://stats.stackexchange.com/questions/185507/what-happens-if-the-explanatory-and-response-variables-are-s
by Houshalter 9y ago
Reminds me of this horrifying stack exchange post: https://stats.stackexchange.com/questions/185507/what-happens-if-the-explanatory-and-response-variables-are-sorted-independently https://stats.stackexchange.com/questions/185507/what-happen...
- SBCRec 9y agowow, that is actually horrifying.
- v4nn4 9y agoWtf wow
- jmkni 9y agoELI5?
- TeMPOraL 9y agoThe manager of the person who asked the question thinks that if you take data in form of pairs (X, Y), split them up, sort independently and combine again, you'll get better results. In fact, such operation obviously destroys the relationship X had to Y, so the result is meaningless.
- jmkni 9y agoHa, gotcha! Maybe if you do it enough times...in the cloud?
- TeMPOraL 9y agoYou'd be better off just going with whatever "result" you want regardless of the data, and save on the AWS costs.
- ardivekar 9y agoNo no, results stored on The Blockchain.
- pavel_lishin 9y agoA chatbot can read them back to us.
- sidlls 9y agoOnly if it's implemented in Rust. Any other language wouldn't be safe.
- yellowapple 9y agoBut Rust is not Web Scale™. Go.js is Web Scale™.
- Buttons840 9y agoDoesn't it also assume you'll have access to the correct answer in production as well? Is X the observation and Y the correct answer, as often indicated by that notation?
- chestervonwinch 9y agoImagine you were trying to measure whether or not increasing X proportionally increases Y. Now imagine you first sort your data points, Xi and Yi, independently -- it will now misleadingly appear like Y increases when X increases since the variables are both sorted. You've scrambled your data (Xi, Yi) to be (Xk, Yj). So you're essentially working with a totally different dataset now.
- jmkni 9y agoIt's actually quite a simple question, just asked using a lot of overly complex language which probably confused the questioner and his boss. It's no different to having a list of key/value pairs and sorting the keys and the values independently, and hoping to get a meaningful result which is absurd.
- stevenbedrick 9y agoThat is an excellent analogy.
- nilkn 9y agoSuppose your dataset consists of the following points. (1,5) (2,3) (3,10) (4,4) Clearly there's really not a linear relationship between the first coordinate and the second coordinate. In other words, if you plot these four points and try to approximate them with a single line in the plane, you just can't do a very good job. The person's manager suggested sorting the second coordinates in this list while keeping the first coordinates fixed, resulting in the following: (1,3) (2,4) (3,5) (4,10) These points are still not collinear, but they certainly can be better approximated by a line than before. The problem is that this is simply a completely different set of points, so a linear approximation here implies nothing about the original dataset.
- abandonliberty 9y agoOMG. This is a data scientist trap. They can't help themselves! It's actually a great question to test fundamental understanding and ability to explain.
- deleted 9y ago[deleted]
- sevensor 9y agoOne of my colleagues (an engineer) suggested something like this when I worked at a factory. My jaw dropped and I just stared at him. I had nothing to say. I guess he's a manager now.
- nirmalpatel 9y agoIs this a joke?
- cleetus 9y agoI can't believe that's real!
- deleted 9y ago[deleted]
- abandonliberty 9y agoMeanwhile I don't know how to get enough votes on my new stack exchange account to enable commenting.