1. A method comprising: receiving, by a processor, a video divided into a plurality of portions, the video having a plurality of objects, each object appearing in one or more of the portions; generating, by the processor, a graphical diagram having a plurality of graphical elements corresponding to the objects, each graphical element having a size corresponding to a number and/or size of the portions in which the object to which the graphical element corresponds appears, the graphical elements having locations within the graphical diagram in correspondence with relationships of appearance of the objects within the portions; and, displaying, by the processor, the graphical diagram on a display device.