Posterior Probability
Candlefocus EditorP(A|B) = P(A) * P(B|A) / ∑ ( P(A) * P(B|A) )
In order for posterior probabilities to be calculated, it is necessary to know the prior probability of the event, as well as the likelihood of a given event B occurring given the occurrence of event A. The likelihoods of all events that can occur must also be calculated which can be done by measuring the frequency of those events from past cases or from the data set of the study.
By using Bayes' theorem and the posterior probability, the probability of an event occurring can be adjusted as new information is obtained. This concept is particularly useful in data analytics, as new data can be obtained and used to update the prior probabilities, enabling more accurate predictions to be made as new data is received. This can be used in many different applications, such as in marketing to predict possible outcomes of particular marketing campaigns based on prior campaigns, or in financial forecasting where the posterior probability can be used to optimize trading models.
By using the posterior probability, it is possible to update prior probabilities in order to make more accurate predictions. This is useful in many different fields, from marketing to data analytics to financial forecasting, as it allows for models to be adjusted as more data or information is gathered or obtained. As such, it is an important concept in Bayesian statistics that enables probabilities to be revised or updated.