Confidence interval

cosmos 3rd April 2019 at 3:29am
Confidence estimation Interval estimation

In many problems of statistical inference the experimenter is interested in constructing a family of sets that contain the true (unknown) parameter value with a specified (high) probability. If X, for example, represents the length of life of a piece of equipment, the experimenter is interested in a lower bound θ for the mean θ of X. Since θ = θ(X) will be a function of the observations, one cannot ensure with probability 1 that θ(X) ≤ θ. All that one can do is to choose a number 1 − α that is close to 1 so that P θ {θ(X) ≤ θ} ≥ 1 − α for all θ. Problems of this type are called problems of confidence estimation, and the sets constructed are called confidence intervals.

Binomial confidence interval

Bayes optimal confidence interval! (I call it Bayesian confidence interval; how close are PAC-Bayes intervals on the Generalization error to be Bayesian optimal? are they even Admissible?)


In this formulation (frequentists), a 95% confidence interfval means that 95% of the times we draw a sample of this type, 95% of the time this confidence interval will include the mean. 95% probability that our interval contains the real mean


Find p_est such that P(e<e_observed) is 0.05. That way, even if p is that high, p will fall within the confidence interval with 95% probability. For confidence intervals, imagine p fixed, and possible e_obs. Then find procedure, (like a fixed interval size, in the simplest case), so that p will fall in the interval with probability alpha

https://docs.google.com/document/d/1QAz45x3maDrs7uVACsJb-wVre_M8GW1hKpjEworLcbI/edit


For the Bayesian analogue see Credible interval