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11 votes
3 answers
1k views

Why do physicists use sigma while biologists use p values/posterior probabilities?

I work in the analysis of biological data, and am familiar with the use of maths to determine a test statistic, and the comparison of this test statistic with a threshold to evaluate a hypothesis. ...
User65535's user avatar
  • 221
1 vote
0 answers
100 views

Connection between mean field inference and mean field theory (physics)

In variational inference, the mean-field family of probability distributions is the set of distributions that factors over its terms (i.e. each component is independent of all others). This allows us ...
900edges's user avatar
  • 399
1 vote
0 answers
79 views

Granger-Causality and Physics

Considering the conversation in "Does y = f(x) imply x granger-causes y", I have a deeper question about Granger-Causality. Suppose I have a leaf flying in the wind and it can only fly back ...
Eric Inclan's user avatar
1 vote
0 answers
44 views

How to determine statistical significance of physics dataset?

I am working on a physics paper, which looks at the dependence of resistivity on physical temperature. I obtained data showing a linear trend of the form $$\rho(T)=\rho_0[1+\alpha(T-T_0)]$$ Based on ...
BooleanDesigns's user avatar
1 vote
1 answer
39 views

Is there any advantage to using $\chi^2$ for checking linear relationship $y(x)$?

At my university (physics major), we are often forced to use $\chi^2$ for checking if $y(x)$, where $y$ and $x$ are measured, is linear. We fit a linear regression $f(x)$ and then use $\chi^2 = \sum_{...
lkky7's user avatar
  • 133
41 votes
4 answers
5k views

Origin of "5$\sigma$" threshold for accepting evidence in particle physics?

News reports say that CERN will announce tomorrow that the Higgs boson has been experimentally detected with 5$\sigma$ evidence. According to that article: 5$\sigma$ equates to a 99.99994% chance ...
Harvey Motulsky's user avatar