19. The system of claim 17 , wherein the knowledge base is a troubleshooting knowledge base which includes a set of cases, each case including a problem with the device and at least one known solution for that problem and wherein the candidate phrases are extracted from at least one of the problems and the solutions.
17. A system for linking textual and physical concepts, comprising: a candidate phrase extraction module for extracting candidate phrases from an associated knowledge base, the knowledge base comprising problems and corresponding solutions for a device, the candidate phrases including noun phrases, and for generating a set of candidate concepts based on the extracted noun phrases; a graphical user interface generator for generating a graphical user interface for a user to generate mapped concepts for physical components of the device by selecting, for each concept to be mapped, a physical component shown on the graphical user interface in a graphical representation of the device and to select at least one of the candidate concepts which is to be linked in memory to that physical component, the graphical user interface generator providing for a user to generate mapped concepts for actions associated with the physical components by selecting, for each concept to be mapped, an action shown in a graphical representation of the physical device and at least one of the candidate concepts for an action which is to be linked to that action, which are then stored in a mapped concept database; an indexing module for indexing the knowledge base based on the mapped concepts, whereby at least some of textual expressions in the knowledge base are linked to a respective physical component through one of the mapped concepts; and a processor which implements the candidate phrase extraction module the indexing module, and graphical user interface generator.