Temperature.

This is the second in a series of articles on the impact of time on the conceptual modeling of business domains. The previous article [6] distinguished three basic temporal data types: instant (point in time), interval (duration of time), and period (anchored duration of time). It then classified temporal object types into once-only (e.g., Date) and repeatable (e.g., WeekDay) object types, It then discussed four kinds of fact type: definitional (truth of instances is a matter of definition), once-only (instances correspond to a single event), repeatable (instances may correspond to multiple events) and time-deictic (the meaning of instances depends on the time of utterance/inscription). Finally, it showed how to model temporal details about point events or period events underlying instances of once-only fact types that are unchangeable. The focus of this article is on modeling of temporal information about events underlying changeable fact types. Three graphical notations are used for examples: second generation Object-Role Modeling (ORM 2) [4, 5] as supported by the open source (Neumont ORM Architect) NORMA tool [3, 7]; the Unified Modeling Language (UML) [8, 9]; and the Barker notation [1] for Entity-Relationship Modeling (ER) [2].