U.S. Department of Energy

Pacific Northwest National Laboratory

Problem Specification

There are two key steps required to specify a signature problem. The first is to determine the phenomenon of interest and the second is to specify the purpose.

The phenomenon of interest is the observable fact or event targeted by the signature. Examples include human disease, network intrusion, the presence of pathogens, or the presence of explosives.

The purpose is the intent or goal of the signature: is it intended to detect, characterize, or predict? The purpose is further defined by the relationship in time between the signature target and the detection of the signature. The purpose is prognostic if the signature is used to detect or characterize targets in the future, diagnostic if it is used to detect or characterize targets in the present, and forensic if it is used to detect or characterize targets in the past.

| Pacific Northwest National Laboratory