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Exactly, my point is it's stupid terminology. I use the word "mean", not "expectation". That brainwashes people actually "expecting" the mean to happen, which i

by dheera 5y ago

Exactly, my point is it's stupid terminology. I use the word "mean", not "expectation". That brainwashes people actually "expecting" the mean to happen, which in this case, it never will. Treating the mean as an expectation of some sort is just not a good formulation to strategize about this game. GGP said "you are expecting a profit of $901" -- I'm not, personally. I'm "expecting" -$100. How about we take a bet? I'll expect -$100, you expect $901. If I win you give me $100, if you win I give you $100, and if neither of us wins we split the $100K. Deal? This is a game theory problem, NOT a statistics problem. In my case the utility of losing -$100 is zero, the utility of gaining $100K is very positive, the utility of missing out on the $100K is extremely negative.

josephcsible 5y ago
Are you saying we should stop using the term "expected value" in cases where it isn't equal to the mode?
- dheera 5y ago
  Yes. I don't know about you but if you have a coin labeled 0 and 1 and flip it it would be mind-bogglingly stupid to expect a 0.5 out of this coin. Just like if you have a coin labeled A and C it would be stupid to expect a B to come out of it. You'd be better off picking either A or C and expecting that instead.
  - Daishiman 5y ago
    I guess you never took stat 101.
    - dheera 5y ago
      Personal attacks not appreciated. No statistics class I took said that a coin with sides A and C can give you a B, or that you could "expect" 0.5 from a bimodal distribution with a delta function at 0 and a delta function at 1. The mean value may be 0.5 but it's not something you would expect to actually happen; if you wanted to maximize the probability that your prediction is correct you'd be better off picking 0 or 1.
      - Daishiman 5y ago
        You're making an entire thread about defending your position against using a term of art the way it's used by professional and academics all over the world. Judging by every reply you're getting, everyone know what they mean when they talk about the expected value of a probability distribution. Just drop it.
      - kortilla 5y ago
        It’s not a personal attack. “Expected value” is a very basic term of art introduced in stats 101. It’s like having a huge argument about a physics problem claiming “force” isn’t mass times acceleration because nobody is “forcing” you to do anything. Back to your 0 or 1 example. 0.5 is the meaningful value to know over any kind of large sampling because that is what matters for “expected value”. It tells me what I should expect overall if I play 1000 times. What you want is called the “mode”. Given a single instance of an event, what is the most frequent value.
        dheera 5y ago
        > “Expected value” is a very basic term of art introduced in stats 101. I already know that. My point is it's shitty terminology, even though it's somehow become a standard. Stats 101 also does NOT tell you to "expect" the expected value to happen. GGGGGP however seems to actually use the value to formulate a strategy, and that's where I'm pointing out that this entire formulation of using stats to approach this problem is flawed. You don't have enough chances at the game such that the mean is a meaningful number to consider. That's also why I always refer to it as the mean even if other people call it "expected value". I hate the term with a passion and I will not yield to the wise guys who wrote the books. Honestly I'd rather not have this discussion in English because this isn't a problem in many other languages. In many languages mean is not called "expected" anything.
bobsmooth 5y ago
>This is a game theory problem, NOT a statistics problem. In my case the utility of losing -$100 is zero, the utility of gaining $100K is very positive, the utility of missing out on the $100K is extremely negative. Calculating utility, or the expected value, is entirely statistics.
- dheera 5y ago
  utility != "expected value" "expected value" != MY expectation utility != statistics on dollars
  - mynameisvlad 5y ago
    Just because you think so strongly that your definition is correct does not make it fact. "Expected value" and its derivatives is a specific term, with a specific calculation. You can't just throw around words and expect others to understand you don't mean the actual definition when you say them. https://www.e-education.psu.edu/eme460/node/730 https://www.e-education.psu.edu/eme460/node/730
    - dheera 5y ago
      I am not arguing over a definition, I'm just saying that the definition sucks and that GGGGGP was actually expecting the "expected value" which I wouldn't do in this case.

by dheera 5y ago

josephcsible 5y ago

Are you saying we should stop using the term "expected value" in cases where it isn't equal to the mode?

dheera 5y ago
Yes. I don't know about you but if you have a coin labeled 0 and 1 and flip it it would be mind-bogglingly stupid to expect a 0.5 out of this coin. Just like if you have a coin labeled A and C it would be stupid to expect a B to come out of it. You'd be better off picking either A or C and expecting that instead.
- Daishiman 5y ago
  I guess you never took stat 101.
  - dheera 5y ago
    Personal attacks not appreciated. No statistics class I took said that a coin with sides A and C can give you a B, or that you could "expect" 0.5 from a bimodal distribution with a delta function at 0 and a delta function at 1. The mean value may be 0.5 but it's not something you would expect to actually happen; if you wanted to maximize the probability that your prediction is correct you'd be better off picking 0 or 1.
    - Daishiman 5y ago
      You're making an entire thread about defending your position against using a term of art the way it's used by professional and academics all over the world. Judging by every reply you're getting, everyone know what they mean when they talk about the expected value of a probability distribution. Just drop it.
    - kortilla 5y ago
      It’s not a personal attack. “Expected value” is a very basic term of art introduced in stats 101. It’s like having a huge argument about a physics problem claiming “force” isn’t mass times acceleration because nobody is “forcing” you to do anything. Back to your 0 or 1 example. 0.5 is the meaningful value to know over any kind of large sampling because that is what matters for “expected value”. It tells me what I should expect overall if I play 1000 times. What you want is called the “mode”. Given a single instance of an event, what is the most frequent value.
      - dheera 5y ago
        > “Expected value” is a very basic term of art introduced in stats 101. I already know that. My point is it's shitty terminology, even though it's somehow become a standard. Stats 101 also does NOT tell you to "expect" the expected value to happen. GGGGGP however seems to actually use the value to formulate a strategy, and that's where I'm pointing out that this entire formulation of using stats to approach this problem is flawed. You don't have enough chances at the game such that the mean is a meaningful number to consider. That's also why I always refer to it as the mean even if other people call it "expected value". I hate the term with a passion and I will not yield to the wise guys who wrote the books. Honestly I'd rather not have this discussion in English because this isn't a problem in many other languages. In many languages mean is not called "expected" anything.

bobsmooth 5y ago

>This is a game theory problem, NOT a statistics problem. In my case the utility of losing -$100 is zero, the utility of gaining $100K is very positive, the utility of missing out on the $100K is extremely negative. Calculating utility, or the expected value, is entirely statistics.

dheera 5y ago
utility != "expected value" "expected value" != MY expectation utility != statistics on dollars
- mynameisvlad 5y ago
  Just because you think so strongly that your definition is correct does not make it fact. "Expected value" and its derivatives is a specific term, with a specific calculation. You can't just throw around words and expect others to understand you don't mean the actual definition when you say them. https://www.e-education.psu.edu/eme460/node/730 https://www.e-education.psu.edu/eme460/node/730
  - dheera 5y ago
    I am not arguing over a definition, I'm just saying that the definition sucks and that GGGGGP was actually expecting the "expected value" which I wouldn't do in this case.