1. A method comprising: reading content stored in a plurality of electronic files, wherein the files belong to a course of learning resources; generating an object-oriented representation of structures of the content, wherein the representation includes objects that represent portions of the content; generating a semantic content model of the content based on the object-oriented representation of the content; receiving instructions to modify the content; modifying the object-oriented representation of the structures of the content in response to the instructions from the user; and modifying the content in response to the modified object-oriented representation of structures of the content.