A method for facilitating document review includes determining an ordered relationship among electronic communication documents in a conversation thread group. The ordered relationship specifies a time sequence of documents in each of one or more conversation threads within the thread group. Each conversation thread begins with the same root document and ends with a different end document. The method also includes causing a visualization of the thread group to be presented to a user via a GUI. The visualization includes graphic elements corresponding to different electronic communication documents, and each element is at a respective position along first and second axes of the visualization in accordance with the ordered relationship. The first axis is indicative of how many electronic communications were sent, within a given conversation thread, after the root document was sent, and the second axis is generally indicative of how many conversation threads are in the thread group.