7. A method comprising: obtaining user context information associated with a user; identifying, based on a plurality of concepts in a first knowledge representation (KR), a group of one or more concepts relevant to the user context information; and providing the identified group of one or more concepts to the user, wherein the first KR includes a combination of modules, the modules including a kernel and a customized module, the kernel being accessible via a second KR, the customized module being customized for the user, and wherein the identifying and the providing are performed at least in part by using at least one processor and a data structure representing the first KR, wherein the customized module is a first customized module, wherein the modules further include a second customized module, the second customized module being customized for the user, and wherein there is a difference between the first and second customized modules.
7. A method comprising: obtaining user context information associated with a user; identifying, based on a plurality of concepts in a first knowledge representation (KR), a group of one or more concepts relevant to the user context information; and providing the identified group of one or more concepts to the user, wherein the first KR includes a combination of modules, the modules including a kernel and a customized module, the kernel being accessible via a second KR, the customized module being customized for the user, and wherein the identifying and the providing are performed at least in part by using at least one processor and a data structure representing the first KR, wherein the customized module is a first customized module, wherein the modules further include a second customized module, the second customized module being customized for the user, and wherein there is a difference between the first and second customized modules. 8. The method of claim 7 , wherein the difference between the first and second customized modules comprises at least one concept and/or relationship that is included in only one of the first customized module or the second customized module.