One of the most useful, coolest technologies that has come down the pipe has been Bayesian calculation and filtering. New from IBM's DeveloperWorks this morning is a great piece covering it.

Paul Meagher introduces Bayesian inference by discussing the basic mathematical concepts involved and demonstrating how to implement the underlying conditional probability calculations using PHP. In this article, the author discusses how Bayesian inference can be used to build an online PHP-based wizard that guides a user through the process making a medical diagnosis. This three-part series features interesting applications designed to help you appreciate the power and potential of Bayesian inference concepts.

It's good that he starts with some basics like conditional probability (the base of the bayesian functionality) and then quickly moves using this functionality to create a probability function. They roam through various formulas, showing you how each relates to the greater whole, and, in the end, help you create a "medical diagnosis wizard" for your benefit...