3 ms·

It's funny because towards the end of the article: > As Scott and his colleagues noted in their paper, if a pathogen grows exponentially and a population recei

It's funny because towards the end of the article: > As Scott and his colleagues noted in their paper, if a pathogen grows exponentially and a population receives a statistically normal distribution of exposures to it, then a lognormal distribution of incubation times should result This makes it seem trivially obvious that you would expect a log normal distribution. I'm conflicted because I'm glad I read an interesting article, but why was it presented as if there were any surprise or mystery to it?

xapata 9y ago
Things that are obvious to one person aren't to another.
- darkerside 9y ago
  Right, and it wasn't something that I knew before reading the article. I appreciate that. What I don't is that there's a fairly simple and likely reason those charts look the way they do. The article makes it seem like a miraculous and unexplained coincidence.
gwern 9y ago
It does seem trivially obvious - if you are already closely familiar with the log-normal. :) I read the first few lines and thought, 'a long tail of infection times? Infections are based on exponential growth. I bet this is a log-normal!' This is because I like the log-normal and notice it, but it's not something which gets a lot of coverage or is routinely taught in statistical material. A similar thing is the tail effects or order statistics of a normal distribution: if you set a cut off or threshold and look at the distribution of samples beyond it, it can look very surprisingly different from the original distribution. This comes up all the time in discussions of IQ, testing, higher education, racism/sexism/bias in general, health & disease, genetics, optimization etc, and keeps surprising the heck out of people because even though it's a statistical triviality, it's both counterintuitive and not typically taught.

3 ms·

It's funny because towards the end of the article: > As Scott and his colleagues noted in their paper, if a pathogen grows exponentially and a population recei

by darkerside 9y ago

xapata 9y ago
Things that are obvious to one person aren't to another.
- darkerside 9y ago
  Right, and it wasn't something that I knew before reading the article. I appreciate that. What I don't is that there's a fairly simple and likely reason those charts look the way they do. The article makes it seem like a miraculous and unexplained coincidence.
gwern 9y ago
It does seem trivially obvious - if you are already closely familiar with the log-normal. :) I read the first few lines and thought, 'a long tail of infection times? Infections are based on exponential growth. I bet this is a log-normal!' This is because I like the log-normal and notice it, but it's not something which gets a lot of coverage or is routinely taught in statistical material. A similar thing is the tail effects or order statistics of a normal distribution: if you set a cut off or threshold and look at the distribution of samples beyond it, it can look very surprisingly different from the original distribution. This comes up all the time in discussions of IQ, testing, higher education, racism/sexism/bias in general, health & disease, genetics, optimization etc, and keeps surprising the heck out of people because even though it's a statistical triviality, it's both counterintuitive and not typically taught.