The Parcel Is Still Where the Map Says It Is
The estimated delivery is between 2pm and 6pm. It is currently 2:07pm. The parcel has been checked three times since 2pm.
The parcel left the sorting facility at 8:43am.
This is known because the tracking page was opened at 9:15am. The parcel's location was logged, understood, and refreshed twice before 9:30am, at which point it had not moved, which was correct behavior for a parcel that had been logged into a vehicle at 8:43am and was now in transit.
The delivery window is 2pm to 6pm. It is 2:07pm.
The Application
The tracking page was opened at 2:00pm because 2pm was the start of the window, and monitoring a window from its start is rational. At 2:04pm, no update had occurred. This was expected but required verification. At 2:07pm, the page was refreshed again, producing the same information.
The parcel is in the area. It is on a vehicle. The vehicle is somewhere between the depot and the door. The tracking system does not know where between those two points. The tracking system shows the last logged event, which was the vehicle departure at 8:43am.
Refreshing the page does not produce new logged events. This is known. The page has been refreshed six times since 2pm.
The Technique
The tracking page was refreshed at: 2:00pm, 2:04pm, 2:07pm, 2:14pm (background check), 2:22pm (back to phone for no reason), 2:31pm (actual check), 2:39pm (the map moved slightly).
The map moved slightly at 2:39pm. The parcel is now in a different location. It has been refreshed four times since the map moved. The map has not moved again.
The Resolution
The parcel arrived at 3:47pm. The door was answered immediately. The person at the door noted this response time with satisfaction.
The total number of tracking page refreshes between ordering and delivery: forty-one. The number of refreshes that produced new information: seven. The number of refreshes that were necessary: approximately four.
The next parcel was ordered that evening. The tracking link was saved immediately.