19. A system comprising: a computing platform coupled to storage device, the storage device comprising a knowledge base, the knowledge base comprising content associated with a plurality of linked subject items, and wherein individual subject items are associated with corresponding user-specific understanding values, and wherein the computing platform performs a method to retrieve and disseminate content associated with the plurality of linked subject items in the knowledge base the method comprising: ranking at least one of a plurality of candidate subject items for presentation to at least one user based on priority values associated with the candidate subject items, wherein the candidacy is determined and the priority values are computed based, at least in part, on: the user-specific understanding values corresponding to the at least one of a plurality of candidate subject items, the understanding values of at least one of a plurality of basic subject items linked to the at least one candidate subject item, and the understanding values of at least one of plurality of advanced subject items linked to the at least one candidate subject item.
19. A system comprising: a computing platform coupled to storage device, the storage device comprising a knowledge base, the knowledge base comprising content associated with a plurality of linked subject items, and wherein individual subject items are associated with corresponding user-specific understanding values, and wherein the computing platform performs a method to retrieve and disseminate content associated with the plurality of linked subject items in the knowledge base the method comprising: ranking at least one of a plurality of candidate subject items for presentation to at least one user based on priority values associated with the candidate subject items, wherein the candidacy is determined and the priority values are computed based, at least in part, on: the user-specific understanding values corresponding to the at least one of a plurality of candidate subject items, the understanding values of at least one of a plurality of basic subject items linked to the at least one candidate subject item, and the understanding values of at least one of plurality of advanced subject items linked to the at least one candidate subject item. 24. The system of claim 19 , wherein user-specific linkage strengths are used to indicate a strength of association between pairs of linked subject items in the knowledge base and the linkage strengths are used in the determination of candidacy and the computation of the priority values.