F. Steimann, " On the representation of roles in object-oriented and conceptual modelling," Data and Knowledge Engineering, vol. 35, pp. 83--848, 2000.  Home/Search   Document Details and Download   Summary   Related Articles   Check

....on part of the programmer, and partly due to the fact that an intuitive conceptualization of interfaces comparable to that of classes is still lacking. 2 A useful conceptualization of JAVA S interfaces It has been noted over and over that many application domain types are roles, not classes [4]. The omnipresent customer for example, or student, EmD] oyee, and Mana9er, are all roles which can be adopted and dropped by instances of class person. That they can be adopted and dropped, that is, dynamically acquired and abandoned, is characteristic for roles. The perennial class person on the ....

....variables ratio the total number of variables (instance variables, formal parameters, and temporaries) declared with an interface divided by the total number declared with a class. 5 Related work The concept of role in conceptual and object oriented modelling has been covered exhaustively in [4]; the technical correspondence of roles and interfaces is made plausible in [5] Both works come with a comprehensive literature review to which the interested reader is referred. The ontological foundations of the role (and hence also the interface) concept are covered in [3] The benefits of ....

F Steimann "On the representation of roles in object-oriented and conceptual modelling " Data & Knowledge Engineering 35:1 (2000) 83-106.

....can be done rapidly by reusing gained experience. This experience can be documented in a form of design patterns [Fowler96, Gamma95] Specifying collaboration as well as working with design patterns is often related with roles and role modeling. There is no consensus on the definition of role [Steimann00]. In our work we define a role as an abstraction of the behavior of an object. A role is always defined in a context that is collaboration with other roles [Genilloud00] The collaboration defines how several roles interact together to achieve a common result. The specification of a collaboration ....

Steimann, F., On the Representation of Roles in Object-Oriented and Conceptual Modelling. Data and Knowledge Engineering 35, 2000(1): p. 83--106.

....for Roles Roles are easy to identify yet they are difficult to represent. They are not merely reified names for the participants in events. Rather, roles have their own characteristics which require that they be treated differently than entities in a knowledge representation scheme. Steimann [14] identified fifteen characteristics of roles, which we ve distilled into these four: 1. Roles are created and destroyed dynamically. Because a role represents the extrinsic features of an entity due to its participation in an event, the role is created when the participation begins. If the entity ....

....can play the role of food. These four characteristics impose requirements on any knowledge representation scheme for roles. The next section assesses past approaches to representing roles in light of these requirements. Previous Approaches to Representing Roles According to Steimann [14], previous research produced three basic approaches to representing roles. The first approach represents a role as nothing but a label assigned to a participant in an event. For example, the employer role labels the agent of an employ event. This approach is simple, but it fails to reify roles as ....

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F. Steimann. On the representation of roles in objectoriented and conceptual modelling. Data and Knowledge Engineering, 35(1):83--106, 2000.

....application of these 1 We ignore the singular plural distinction for this working note 2 Or, to be fair, we should query all slots, as there is no justification for picking just the parts slot. 2 view classes by selectively installing isa links, or by using an adjunct instance approach [Steimann, 2000]. 2.2 An Example For the rest of this note, we will use prototypes to encode views. As a toy example, consider three prototypes, encoding three di#erent views of an airplane: 1. A Structural View This view encodes a (very) simplified representation of the top level partonomic structure of an ....

Steimann, F. (2000). On the representation of roles in object-oriented and conceptual modeling. Data and Knowledge Engineering, 35(1):83--106.

....it can play different roles. Usually the notion of role is linked with change in time. An object is only one thing but it can play different roles during its lifetime. The use of roles in object orientation is reviewed in detail by Pernici [45] Albano et al. 46] Wong et al. 47] and Steimann [48]. The use of roles in the specification of ontologies is discussed in Guarino [32] The concept of role as interfaces as we use in the implementation of this work is reviewed in Steimann [49] One of the most common uses of roles is to represent changes in an object during its lifetime. The ....

....that habitat inherits from a more related entity in the biological sense, thus avoiding a too strong dependence on the geographic point of view. Another reason for using lake as a role is to make it easier to obtain metadata and data from other sources. A role can be viewed in different ways [48]. First, a role is viewed as a named relationship. This point of view stresses that roles exist only within some particular context. Second, a role can be viewed as a specialization or a generalization. The problem with this point of view is that it contradicts Guarinos [52] and mixes the dynamic ....

F. Steimann, On the Representation of Roles in Object-Oriented and Conceptual Modelling, Data & Knowledge Engineering, vol. 35, pp. 83-106, 2000.

....stand in relation to other individuals, and they can enter or leave the extent of the concept without losing their identity. From this definition it emerges that the ability of recognising whether rigidity holds for some property # is essential in order to distinguish whether # is a role. In [25] Steimann presents a list of the features that have been associated in the literature with roles. Some of these features are conflicting and, as pointed out, no integrating definition has been made available. However, from the di#erent definitions available, it can be derived that the notion of ....

....are acquired and relinquished in dependence either of time or of a specific event. For example the object person acquires the role teenager if the person is between 11 and 19 years old, whereas a person becomes student when they enroll for a degree course. Moreover, from the list of features in [25] it emerges that many of the characteristics of roles are time or event related, such as: an object may acquire and abandon roles dynamically, may play di#erent roles simultaneously, or may play the same role several time, simultaneously, and the sequence in which roles may be acquired and ....

[Article contains additional citation context not shown here]

F. Steimann. On the representation of roles in object-oriented and conceptual modelling. Data and Knowledge Engineering, 35:83--106, 2000.

....part of the programmer, and partly due to the fact that an intuitive conceptualization of interfaces comparable to that of classes is still lacking. 2. A USEFUL CONCEPTUALIZATION OF JAVA S INTERFACES It has been noted over and over that many application domain types are roles, not classes [4]. The omnipresent Custoer for example, or Student, Eeployee, and Manager, are all roles which can be adopted and dropped by instances of class P e r s o n. That they can be adopted and dropped, that is, dynamically acquired and abandoned, is characteristic for roles. The perennial class Person on ....

....6 For better readability, the reciprocals have been used in the ta ble. In the future, we hope to see higher utilization of interfaces, so that the ratios can be reversed. 16 5. RELATED WORK The concept of role in conceptual and object oriented modelling has been covered exhaustively in [4]; the technical correspondence of roles and interfaces is made plausible in [5] Both works come with a comprehensive literature review to which the interested reader is referred. The ontological foundations of the role (and hence also the interface) concept are covered in [3] The benefits of ....

Steimann, F. On the representation of roles in objectoriented and conceptual modelling, Data & Knowledge Engineering 35:1 (2000), 83-106.

....different roles. 3. ROLE ORIENTED MODELING 3.1 Natural Types versus Role Types Classification is perhaps the oldest human concept for organizing the universe. However, classification is an utterly artificial construct which, although capable of structuring nature, is itself not found in nature [21, 30]. Instead, it occurs that the concept of a prototype, together with Wittgenstein s family resemblances, more adequately abstracts from and orders individual entities of which there is such a huge diversity. This view appears particularly apt for the classification of content which, by its nature, ....

F. Steimann. On the representation of roles in object-oriented and conceptual modelling. Data and Knowledge Engineering, 35(1):83--106, 2000.

....and the implements keyword of the JAVA programming language, specifying the instances of which classes can be assigned to variables of which interface type. The full semantics of this relationship, especially with regard to intensions and extensions, is a little more complicated and detailed in [3, 5]. 2.6 Attributes Each class comes with a set of attributes. Each attribute is modelled as an unary function from the extension of the class to some value domain, namely the extension of another class. Again, we refrain from making a distinction between object and primitive types. Many valued ....

....time indexed) parts of a model. All attempts to increase the expressiveness at the (atemporal) type level must appear misled investments by comparison. The above definition of a core abstract syntax uses natural language and the formal notation of set theory and order sorted predicate logic [1, 3]; it could also be depicted graphically, for instance in UML, given that a UML diagram can be drawn that has the same meaning as the above prose. Because UML is intended for software modelling and not for defining a language, we have no interest in doing so and since leave it as an academic ....

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F Steimann "On the representation of roles in object-oriented and conceptual modelling" Data & Knowledge Engineering 35:1 (2000) 83--106.

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F. Steimann, " On the representation of roles in object-oriented and conceptual modelling," Data and Knowledge Engineering, vol. 35, pp. 83--848, 2000.

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F. Steimann, "On the representation of roles in object-oriented and conceptual modelling," Data and Knowledge Engineering, vol. 35, pp. 83--848, 2000.

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Steimann, F. (2000b). On the representation of roles in object-oriented and conceptual modelling. Data & Knowledge Engineering, 35, 1, 83--106.

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Steimann, F. (2000) On the representation of roles in objectoriented and conceptual modelling. Data and Knowledge Engineering no 35, pp 83-106.

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F. Steimann. On the representation of roles in object-oriented and conceptual modelling. Data and Knowledge Engineering, 35:83--106, 2000.

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Friedrich Steimann. On the representation of roles in object-oriented and conceptual modelling. Data and Knowledge Engineering, 35(1):83--106, 2000.

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Steimann, F.: On the Representation of Roles in Object-Oriented and Conceptual Modeling. Data & Knowledge Engineering. 35(1) (2000) 83-106

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F. Steimann. On the Representation of Roles in ObjectOriented and Conceptual Modelling. Data & Knowledge Engineering, 35(1):83--106, 2000.

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F. Steimann, `On the representation of roles in object-oriented and conceptual modelling', Data and Knowledge Engineering, 35, 83--106, (2000).

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F. Steimann. On the representation of roles in object-oriented and conceptual modelling. Data & Knowledge Engineering, 35(1):83--106, 2000.

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F. Steimann. On the representation of roles in object-oriented and conceptual modelling. Data & Knowledge Engineering, 35(1):83--106, 2000.

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Steimann, F.: On the representation of roles in object-oriented and conceptual modeling. Data & Knowledge Engineering 35:1 (2000) 83--106

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F. Steimann, On the representation of roles in object-oriented and conceptualmodeling DataKnowledg Eng 35 (October) (2000) 83--106.

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Steimann, F.: On the Representation of Roles in Object-Oriented and Conceptual Modeling. Data & Knowledge Engineering. 35(1) (2000) 83-106

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F. Steimann. On the representation of roles in object-oriented and conceptual modelling. Data and Knowledge Engineering, 35:83--106, 2000.

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Steimann, F. "On the Representation of Roles in Object-Oriented and Conceptual Modeling," Data & Knowledge Engineering, 35(1):83--106, 2000.

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