Embodiments relate to methods and systems for building representations of related subjects. The representations may include a plurality of nodes, each being associated with a subject. Users may be able to access records and/or source documents related to a plurality of subjects and add or modify node characteristics based thereon. Users may interact with (e.g., by adding to or modifying) documents, files, and/or records and may also make other changes or additions to nodes in the system. A process may then identify what other users may be interested in such interaction and why. For example, a score may be associated with the interaction and other users based on factors such as whether the users have linked to the document, file or record and/or the node the interaction may apply to. Interacting users, identified users, and interaction details may be stored in a database. Identified users may be notified of the interaction.