Microsoft Word OpenIssuesInOO. doc

The level of abstraction. To understand the complications of the application domain, we 

have to analyse the phenomena and develop concepts for grasping the relevant 

properties of the phenomena that we consider.  In the programming process this 

corresponds to designing the classes and their attributes and to organising the classes 

into a class/sub-class hierarchy.  At this level we obtain a simple and systematic 

understanding of the phenomena in the referent system. 

The level of thought concreteness. The understanding corresponding to the abstract level is 

further developed to obtain an understanding of the totality of the application domain.  

By having organised the phenomena of the application domain by means of concepts, 

we may be able to understand relations between phenomena that we did not understand 

at the level of empirical concreteness. We may also be able to explain why things 

happen and  to predict what will happen. 

The above is an identification of three levels appearing in the process of creating and 

producing knowledge. In this process the means used for organising and understanding 

knowledge depend on the perspective of the person. Object-orientation is an example of a 

perspective. Other examples are function-oriented and constraint-oriented.