3. The system of claim 1 , wherein the visualizations include a two-tier visualization that includes: a first level that comprises a plurality of sheet icons; and a second level that comprises a plurality of user icons.
3. The system of claim 1 , wherein the visualizations include a two-tier visualization that includes: a first level that comprises a plurality of sheet icons; and a second level that comprises a plurality of user icons. 6. The system of claim 3 , wherein the two-tier visualization further includes one or more connections between the sheet icons in the first level and the user icons in the second level to indicate interactions by the users related to the sheets.