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The pneumonia-asthma example seems to be an example of a Simpson's paradox [1]. The doctors acted on a strong (accurate) belief about asthma sufferers contract
by venning 10y ago
The pneumonia-asthma example seems to be an example of a Simpson's paradox [1]. The doctors acted on a strong (accurate) belief about asthma sufferers contracting pneumonia and acted in such a way that the data obscured an actual causal link (asthma as an aggravating factor to pneumonia). This is opposed to the canonical Simpson's paradox where doctors acted on a strong (inaccurate) belief about severe kidney stones [1a] and again produced lopsided data that hid the best treatment option until the paradox was identified.
Humans have a very hard time uncovering so-called "lurking variables" [2] and identifying such paradoxes. I don't see how a neural network (or other machine learning tool) could do so on their own, but I don't know that much about machine learning. So, I guess I have two questions for the experts out there:
* If all training data is affected by a confounding variable, can a machine learning algorithm identify its existence, or is it limited by only knowing a tainted world?
* Once we have identified such lopsided data and understood its cause, how do you feed that back into your algorithm to correct for it?
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[1] https://en.wikipedia.org/wiki/Simpson%27s_paradox https://en.wikipedia.org/wiki/Simpson%27s_paradox
[1a] https://en.wikipedia.org/wiki/Simpson%27s_paradox#Kidney_stone_treatment https://en.wikipedia.org/wiki/Simpson%27s_paradox#Kidney_sto...
[2] https://en.wikipedia.org/wiki/Confounding https://en.wikipedia.org/wiki/Confounding
- Houshalter 10y agoOne method of fixing this would be to have the neural network make 2 predictions. The first would be to predict what decision the doctor would make. The second would be to predict what decision is actually likely to lead to the best outcome. In cases where it's very likely the doctor would make a different decision, it should flag it for human review.
- Inlinked 10y ago> Once we have identified such lopsided data and understood its cause, how do you feed that back into your algorithm to correct for it? This is tackled in the recently popular field of study called 'counterfactual inference'. http://leon.bottou.org/talks/counterfactuals http://leon.bottou.org/talks/counterfactuals