The MSBNX system allows model builders to decorate nodes (variables) or models with additional information, such as text strings or numbers that may be important to the author. In addition, there are some types of predefined information that MSBNX uses for specialized tasks.
The primary use for standard properties in MSBNX is to support decision-theoretic troubleshooting and diagnosis. In addition, properties can be important to developers who use MSBNX and its components in their own programming efforts; see MSBNX components for more information.
Note: You will not typically need the information in this topic unless you intend to build troubleshooting models or perform advanced programming functions.
There are three basic groups of information associated with a model and its nodes.
Attributes (or implicit properties). These are data that are always present for a node/variable. Each node has a name string and a description string.
State Names. These are names assigned by the author to the discrete states of a probabilistic variable. There must be at least two such names.
Property Type-based Properties. These are generally user-defined data useable for any purpose.
To create a user-defined property item, you must first create a property type. A property type is a name given to a particular class of data. Each property type must also have an associated information representation data type. The possible data types are:
String
Real (or floating-point) number
Array of string
Array of real
Enumerated list of names
As an example, assume that the variables or nodes in a model represent records in a database, and that you'd like to associate that information with each variable. Assuming each record in the database has an associated numeric key, you would need to declare a property type (let's call it "DatabaseKey"), and then define a value for this property type for each variable in the model.
To do this, you would use the Model and Node Properties window.
In other words, you must declare each type of information so that MSBNX knows how to validate it as it's entered. Both the property type and property value information are stored in the model when it is saved to disk.
Certain property type names are reserved by Microsoft Research and are vital to such features as troubleshooting and the handling of add-in modules. You are not allowed to create property type names beginning with MS_ or DTAS_.
Application of Properties
Once a property type has been declared, any node in the model can be given a value for the new type. In addition, the model itself can be given properties. See Model and Node Properties window information for more details.