File formats for OpenBayes

At the UAI'01 meeting, and on the OpenBayes list, a lot of interest was expressed in representing graphical models in a standardized file format. This issue was already discussed at length at earlier UAI meetings. The result was the XML-BIF format. (This is different from the earlier BIF format, and the recent XBN format used by Microsoft.)

• As of August 2001, only a small number of programs read/write the XML-BIF format (JavaBayes, Genie and Netica). It would be useful to write a parser in Matlab so BNT can read this format.

• Here is an open-source Java program that can convert between the different file formats. (See Bayes net repository for a list of some common formats).

• The XML-BIF format was mostly designed with discrete, static Bayes nets in mind. It will clearly need to be extended to handle continuous-valued nodes and temporal models. For some suggestions, see Proposed extensions to BNIF, by Robert Dodier.

• Extend the format to handle undirected graphical models.

• Extend the format to handle complex scientific models, e.g., Reusable probabilistic models for scientific data by Michael Turmon (JPL).

• A key question is whether the file format should contain information about the graphical appearance of the model --- see the discussion of GUIs.

• In addition to a file format for models, David Heckerman suggested a file format for data (to describe e.g., whether values are missing at random).