Evaluating hypermedia and learning: methods and results from the Perseus Project
The Perseus Project has developed a hypermedia corpus of materials related to the ancient Greek world. The materials include a variety of texts and images, and tools for using these materials and navigating the sytem. Results from a three-year evaluation ...
A nested-graph model for the representation and manipulation of complex objects
Three recent trends in database research are object-oriented and deductive databases and graph-based user interfaces. We draw these trends together in a data model we call the Hypernode Model. The single data structure of this model is the hypernode, a ...
On the expressive power of query languages
Two main topics are addressed. First, an algebraic approach is presented to define a general notion of expressive power. Heterogeneous algebras represent information systems and morphisms represent the correspondences between the instances of databases, ...
Probabilistic information retrieval as a combination of abstraction, inductive learning, and probabilistic assumptions
We show that former approaches in probabilistic information retrieval are based on one or two of the three concepts abstraction, inductive learning, and probabilistic assumptions, and we propose a new approach which combines all three concepts. This ...