A system and technique for visualizing changes and trends in performance data over a network path are disclosed. More specifically, a network management system generates and displays an object that represents data for one or more performance characteristics related to a plurality of network nodes in the network path. The object is dynamically updated to include updated data related to the one or more performance characteristics. In one embodiment, a representation of the updated data is superimposed over representations of previously collected data relating to the performance characteristics. The transparency of the representations associated with the previously collected data may reflect a difference in time between the current time and the time at which the data was collected. In another embodiment, a timeline is included in the object that tracks the state of the object at one or more previous points in time.