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Predictions and probabilites seem unrelated, except in mathematical models which attempt to make "predictions" through probabalistic models. Perhaps you've spen

by c3534l 4y ago

Predictions and probabilites seem unrelated, except in mathematical models which attempt to make "predictions" through probabalistic models. Perhaps you've spent so much time reading about machine learning that you've gotten the concepts confused. I would go so far as to say that a prediction that comes with a probability is not a true prediction, but an estimate masquarading as one.

kqr 4y ago
Quite the opposite! A prediction is an estimation of the most likely outcome in a binary event. I mean, I get that just saying the above seems to confirm your "too much machine learning" hypothesis, but I guarantee you that's not the case. At my own peril, I'm too old fashioned to have read much about machine learning. What I can say is that when making strategic and tactical decisions that affect a lot of people, I have found it incredible to know things like "I am 85 % sure we will not make the next release in time" (an actionable prediction) compared to "there's no way we'll make the next release in time" (when in fact there's still a 15 % chance we will, if we take proper action now.)
- c3534l 4y ago
  It most definitely is not. Confidence and predictions are orthogonal concepts outside of stats and ML. A gambler makes predictions, but may have no confidence in winning. A scientific model may produce predictions with no associatel claims of probability or even validity. It is perfectly grammatically and semantically correct to say that someone made a prediction that they themselves do not believe to be the most likely outcome.
  - kqr 4y ago
    Any gambler that makes a prediction without internally associating it with a probability is one that's most likely losing money. You simply cannot consistently make positive-EV bets without considering the probabilities of your predictions. (Heck, EV is the linear combination of probability and payoff.) A scientific model almost always includes a very specific kind of probability: the p value. The best scientific models are also validated externally and have the results of that experiment reported -- as probabilities: false positive and false negative rates are common concepts to discuss that. I completely agree that one can predict something that one does not believe to be the most likely outcome. But in order to even say that, you have to be implying that there is at least a partial order from "least likely" to "most likely" and that order is commonly referred to as probability. (Edit: oh, I see where you got the "most likely" from. By convention, in a binary prediction, the prediction itself is stated in terms of the most likely outcome, with a confidence between 50 % and 100 %. It is of course possible to state the other side of the event with a confidence level < 50 % -- it's just not the way these things are usually presented.)
    - c3534l 4y ago
      > Any gambler that makes a prediction without internally associating it with a probability is one that's most likely losing money. The very fact that this idea is expressible proves that you're combining two different ideas in your head. You're seeing the utility in making accurate predictions then, despite being perfectly capable of talking about predictions which aren't estimates, pretending that they're the same concept. I of course don't need to appeal to your own confused words, because we live in a world where dictionaries exist.
      - kqr 4y ago
        Sure, I feel like that's what I've been trying to say all along: you can make a prediction without saying at what confidence level, but it doesn't mean anything to anyone other than perhaps to yourself, because only you know how strongly you believe in it.

by c3534l 4y ago

kqr 4y ago

Quite the opposite! A prediction is an estimation of the most likely outcome in a binary event. I mean, I get that just saying the above seems to confirm your "too much machine learning" hypothesis, but I guarantee you that's not the case. At my own peril, I'm too old fashioned to have read much about machine learning. What I can say is that when making strategic and tactical decisions that affect a lot of people, I have found it incredible to know things like "I am 85 % sure we will not make the next release in time" (an actionable prediction) compared to "there's no way we'll make the next release in time" (when in fact there's still a 15 % chance we will, if we take proper action now.)

c3534l 4y ago
It most definitely is not. Confidence and predictions are orthogonal concepts outside of stats and ML. A gambler makes predictions, but may have no confidence in winning. A scientific model may produce predictions with no associatel claims of probability or even validity. It is perfectly grammatically and semantically correct to say that someone made a prediction that they themselves do not believe to be the most likely outcome.
- kqr 4y ago
  Any gambler that makes a prediction without internally associating it with a probability is one that's most likely losing money. You simply cannot consistently make positive-EV bets without considering the probabilities of your predictions. (Heck, EV is the linear combination of probability and payoff.) A scientific model almost always includes a very specific kind of probability: the p value. The best scientific models are also validated externally and have the results of that experiment reported -- as probabilities: false positive and false negative rates are common concepts to discuss that. I completely agree that one can predict something that one does not believe to be the most likely outcome. But in order to even say that, you have to be implying that there is at least a partial order from "least likely" to "most likely" and that order is commonly referred to as probability. (Edit: oh, I see where you got the "most likely" from. By convention, in a binary prediction, the prediction itself is stated in terms of the most likely outcome, with a confidence between 50 % and 100 %. It is of course possible to state the other side of the event with a confidence level < 50 % -- it's just not the way these things are usually presented.)
  - c3534l 4y ago
    > Any gambler that makes a prediction without internally associating it with a probability is one that's most likely losing money. The very fact that this idea is expressible proves that you're combining two different ideas in your head. You're seeing the utility in making accurate predictions then, despite being perfectly capable of talking about predictions which aren't estimates, pretending that they're the same concept. I of course don't need to appeal to your own confused words, because we live in a world where dictionaries exist.
    - kqr 4y ago
      Sure, I feel like that's what I've been trying to say all along: you can make a prediction without saying at what confidence level, but it doesn't mean anything to anyone other than perhaps to yourself, because only you know how strongly you believe in it.