Object Oriented Database Systems should allow their objects to play multiple roles and to change roles in their lifetime. We describe a data model, based on classes, is-a hierarchies, and complex types, that allows objects to belong to several classes, so to play multiple roles. Then we propose a declarative query language to access objects from multiple perspectives, and an update language to ...

in traditional bazaars social interactions, parallel to economic and movement interactions, created a mixed urban space which was dynamic, lively and attractive to the audience. however, modern shopping centers and shopping malls are economy focused and void of variety of urban spaces like traditional bazaars. the presence of public open spaces and urban squares undetectable from traditional ba...

Multiple conceptualizations of the interrelation between assessment and learning yield three notions of assessment: assessment of learning, assessment for learning, and assessment as learning. This paper aims at uncovering roles and obstacles of assessment for learning and assessment as learning in English language classrooms in Hong Kong. Grounded upon the theory of constructivism and the noti...