1. A method for displaying a layout of at least a portion of a node-edge graph, wherein the layout changes over time according to operations performed on the node-edge graph, the node-edge graph including nodes coupled by edges, the method comprising: representing an operation as a tuple of operation type, data tuple, actor and time, wherein the operation type describes a type of operation performed on a data item, wherein the data tuple specifies an item that is the subject of the operation type, wherein actor identifies an entity that is changed the graph by causing the operation on the data item, and wherein the time specifies a time at which the operation occurred; determining a time interval; identifying the operations that occurred within the time interval; and using the operation representations to generate a display of a layout that changes over the time interval.