Bayesian Statistics Flashcards
Bayesian statistics
Probability of an event expressed from 0-1
Bayes theorem
Posterior = likelihood x prior / marginal
Components of Bayes theorem
-Posterior- probability the hypothesis is true given the data
-Likelihood- how probable the data is given the hypothesis is true
-Prior- how probable was hypothesis before observing data
-Marginal- how likely you are to see this data regardless of the hypothesis
Bayes factor
-Assessing the relative plausibilities of competing hypotheses H0 and H1
-Strength of evidence in favor of one hypothesis among two competing hypotheses
-More lower than 1 = H0
-More higher than 1 = H1
-Interpretation- 8 means there is 8 times more evidence for H1 than H0
Similarities with frequentist
-Use some similar models
-Both can be used for estimation and hypothesis testing
Differences from frequentist
-No p-values to interpret coefficients
-No reliance on null hypothesis
-Must explicitly state prior knowledge
Advantages
-Realistic estimates
-Intuitive interpretations
-Requires you to know your area and be specific
-Tells us the answer to what we want to know