In some embodiments, a non-transitory processor-readable medium stores code representing instructions for execution by a computer processor. The instructions cause the processor to produce a list of subjects by identifying a plurality of subjects based on information associated with an analyst-selected topic. The list of subjects is expanded to include subjects that have a relationship with at least one subject from the first list of subjects. Subjects are removed from the list based on either a filter or a scoring threshold. The expanding and removing subjects is iterated until the list of subjects is substantially stable to produce a final list of subjects. A graphical network is defined based on the final list of subjects and a signal is sent representing the graphical network (e.g., to a computer monitor for display).