• Probability can either be interpreted as a long-run frequency (Frequentist) or a measure of belief and uncertainty (Bayesian)
  • Bayes’ Rule is a good framework for many things. Update conjectures based on supporting evidence that is likely observed.
  • The hyperparameters of a model refer to the parameters of the distribution of the priors (from a Bayesian Perspective). The hyperparameters encode our beliefs about the distribution.

Central Limit Theorem

  • Assumption: We have random variables that are independent and identically distributed each with mean and .
  • The Central Limit Theorem states that as , then the distribution of the sum approaches the Normal Distribution.
  • Another way to say this is that the sampling distribution tends towards the normal distribution for a large number of samples even if the original variables are not normally distributed.
  • The implication is that analysis using normal distributions are usually sufficient since many distributions tend to this in the limit.

Monte Carlo Simulation

  • Monte Carlo is one approach to approximating a function of a random variable. This is done by approximating the probability distribution of the function by taking many samples and then taking the empirical probability distribution.
  • More formally, it approximates
    Where .
  • By the Central Limit Theorem, the above approximation becomes better with more samples. This can be quantified using the standard error computed as

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