Patent ID: 7231439

Claim:
A method in a computer for providing information about a current state that is modeled with multiple attributes, the method comprising: receiving from a first source an indication of a current ability to supply values for an indicated one of the state attributes of the modeled current state; after receiving an indication from a client for a value of the one attribute, supplying to the client a value for the one attribute received from the first source; after the supplying of the value received from the first source, receiving from a second source an indication of a current ability to supply values for the one attribute; after receiving an indication from the client for a value of the one attribute, supplying to the client a value for the one attribute based on values received for the one attribute from the first and second sources by, before supplying the value to the client, determining whether the value to be supplied satisfies a criteria indicated for the requested value; and if it is determined that the value does not satisfy the indicated criteria, requesting at least one of the first and second sources to supply a value for the one attribute that satisfies the indicated criteria; receiving in response to the requesting at least one additional value for the one attribute that satisfies the indicated criteria; and supplying to the client a value for the one attribute based on the received additional values; after the supplying of the value based on the values received for the one attribute from the first and second sources, receiving from the first source an indication of a temporary current inability of the first source to supply values for the one attribute; and after receiving an indication from the client for a value of the one attribute, determining that the first source is currently unable to supply values for the one attribute and that the second source is currently able to supply values for the one attribute, and in response supplying to the client a value for the one attribute received from the second source.