Diagramming Imprecise and Incomplete Temporal Information

Abstract

Incomplete and imprecise temporal data is abundant in various branches of science and technology as well as everyday life (e.g., “$A$ began after 1066 but before 1069 and ended after 1245”, “$B$ took place no later than 156 BC”). While point-circles and lines/bars have been traditionally used to depict precise temporal points and intervals, it is unclear how imprecise and incomplete temporal data can be effectively visualized or even represented. This paper suggests an intuitive diagrammatic notation for visualizing both imprecise and incomplete temporal information. It suggests using traditional whiskers with edges to depict temporal imprecision and whiskers without edges to depict incomplete temporal entities. This notation can be easily incorporated into linear temporal visualizations, such as historical timelines, Gantt charts, and timetables, to identify gaps in temporal information. The paper lays down the diagrammatic elements of the notation and illustrates their applicability to all standard relations between temporal entities. It also shows how these elements can be combined to produce complex timelines. Some possible future directions are also outlined.