GFO Part I Basic Principles
           
  ontomed Theories Concepts Applications  
 
Ontological
Investigations
Conceptual
Modelling
Onto-Builder
 
 
Axiomatic
Foundations
Domain
Ontologies
Onco-Workstation
 
 
Metalogical
Analyses
Ontology
Languages
SOP-Creator
 
           
 
 

Onto-Med >> Theories >> GFO Part I Basic Principles

 
   

12.3 Meta-level Status of Roles

Given that the general approach to roles is initially independent of other GFO categories, as well as the diversity of individuals introduced as roles, leads us to question why all roles should fall within the same category. Stated differently, what should the intrinsic commonalities between processual and relational roles be? We must admit that there are none - a fact that lies in the nature of category ``role'' itself, because, under a meta-level perspective, all general role characteristics apply to ``role'' itself.

These meta-level aspects further relate to the account of roles given by Guarino (and colleagues), who characterizes ``role'' as a meta-category of relationally dependent and anti-rigid categories (41,28). The latter means that for each instance of a role category, it is not essential to instantiate that category. These criteria can be reconstructed in GFO, where relational dependence corresponds to our contexts and anti-rigidity must be re-interpreted in terms of player universals. Roles in GFO differ from this approach in the sense that (1) there are role individuals, and (2) it may be essential to play a role. For instance, it is essential that the natural number two is a factor of four, and it is likewise essential that each human is a child. Anti-rigidity thus does not hold for every player universal. Nevertheless, in most cases it is a useful indicator for detecting player universals, and thus roles.

Robert Hoehndorf 2006-10-18
 
       
     
     
     

   
     
     
       
 

deutsch   imise uni-leipzig ifi dep-of-formal-concepts