Ambiguities In Object Specifications In View Of Data Testing

Checking data only relying on their specification is of importance when using neutral or standardized object models. Ambiguities arise during the tests because of specifications leaving a certain degree of freedom to the implementation. Based on an experimental background the observations and reflections about the reasons are systematically presented. It turns out that the transition (or mapping) from a specification of an object to a physical instance (or data set) has to take into consideration when defining neutral models. This transition which often has been seen as a technical question of the implementation or as the internal (hided) feature of a system appears as a particular point of the concept besides the specification. One crucial point is the instance handling with respect to assign and comparison operations. The mapping from a specification into a database can be realized in various manners which leads to interpretation defects when testing independently. Another point is the weak scope definition in specifications. Several ambiguities are caused by it. A very frequent reason of misunderstandings is the imprecise or wrong understanding of the different relations between objects, logical and physical instances. There are approaches for more clear specifications. The last point is the representation of failures or more generally of the state of instances. A concept based on multiple inheritance seems to increase the abstraction level of state specifications on the same level as the used specification language is of. 1. Physikalisch-Technische Bundesanstalt Berlin. Research partly done while at International Computer Science Institute (ICSI), Berkeley, California, as exchange visitor 2. Technical Report of ICSI