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S Aug 28, 2020 at 18:01 history bounty ended CommunityBot
S Aug 28, 2020 at 18:01 history notice removed CommunityBot
Aug 28, 2020 at 11:21 vote accept monade
Aug 27, 2020 at 14:14 comment added kjetil b halvorsen See also stats.stackexchange.com/questions/403575/…
S Aug 27, 2020 at 13:57 history suggested Gerardo Duran-Martin CC BY-SA 4.0
Probit function has mean 0; remove "z" component from the distribution.
Aug 27, 2020 at 13:31 review Suggested edits
S Aug 27, 2020 at 13:57
Aug 27, 2020 at 13:22 answer added Gerardo Duran-Martin timeline score: 2
Aug 20, 2020 at 17:51 comment added whuber The double exponential distribution is the location-scale family determined by the distribution with density function $f(x)=\exp(-|x|)/2.$
Aug 20, 2020 at 16:47 comment added monade Thanks, this question is an excellent resource. The double exponential error would be $\frac{e^{-x}}{(1 + e^{-x})^2}$ (using the notation of my question)?
Aug 20, 2020 at 16:31 comment added whuber If I follow you correctly, you are asking how logit and probit models might be related. Although the mathematical relationship is not simple, in practice they behave so similarly that they are considered interchangeable. Replacing the Gaussian error by a double exponential ("Laplacian") error makes the two approaches equivalent. Perhaps your questions are all satisfactorily addressed at stats.stackexchange.com/questions/20523/…?
S Aug 20, 2020 at 16:26 history bounty started monade
S Aug 20, 2020 at 16:26 history notice added monade Draw attention
Aug 18, 2020 at 14:19 history edited monade CC BY-SA 4.0
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Aug 18, 2020 at 14:13 comment added monade I now realize your misunderstanding. $p_1$ and $p_2$ are two alternatives to achieve the same thing: modeling noisy perceptual choices. (your first question sounded like you thought that I add Gaussian noise p2 on top of the choice probabilities of p1, which of course would not make sense)
Aug 18, 2020 at 14:01 comment added monade $p_2$ is the probability of choosing the positive stimulus category, given an observation $x$. The idea is that I fit both models ($p_1$ and $p_2$) to the choice data and obtain values for β and σ. One question would be whether the expected values of β and σ are related in terms of a formula.
Aug 18, 2020 at 13:59 comment added Tim I'm not sure what you mean by $p_2$ in here. What exactly this ought to be?
Aug 18, 2020 at 13:57 comment added monade I had a typo in $p_2(x)$, maybe things become more clear now.
Aug 18, 2020 at 13:56 comment added Tim Than what you mean by "relation" between them? You could pick arbitrary $\sigma$ to generate $x$ and then multiply it by another arbitrary $\beta$ and use logistic transformation to generate such data, so both can be completely independent from each other.
Aug 18, 2020 at 13:56 history edited monade CC BY-SA 4.0
added 8 characters in body
Aug 18, 2020 at 13:49 comment added monade Where did you see probability + Gaussian noise? My assumption is that there is Gaussian noise around each observation $x$, where $x$ is the stimulus variable, not a probability.
Aug 18, 2020 at 13:47 comment added Tim Probabilities are bounded to $[0, 1]$ while normal distribution is unbounded $(-\infty, \infty)$, so probability + Gaussian noise is not probability any more since it goes outside the bounds... What exactly do you mean by their relation?
Aug 18, 2020 at 13:43 history asked monade CC BY-SA 4.0