Capabilities and biases of learning technologies are examined in light of four widely accepted principles: deep content knowledge, dialogue, agency, and collaboration. Software that supports these principles must focus students' attention on ideas rather than topics or tasks and should foster high levels of "epistemic agency," providing students…

Demonstrates that hierarchical naming schemes--one with a single namespace and fixed root spread over all machines in a distributed system, and a second with total namespace composed of some aggregation of individual namespaces of each component system's filestores--can coexist in distributed computer systems. Combined system's design is…

Discusses science mapping in the general context of information visualization and reviews attempts to construct maps of science using citation data, focusing on the use of co-citation clusters. Reports new work on a dataset of 36,00 documents using simplified methods for ordination and nesting maps hierarchically. Also discusses virtual-reality…

Describes a collaborative, reuse hypertext system, called MUCH (Many Using and Creating Hypertext). The novel browsing and retrieval characteristics of the system are based on a semantic net connecting documents, thesauri, and discussions. Word patterns are documented for reuse, creating and reorganizing network traversal according to user…

Describes the components of a hypertext system and discusses possible applications from the model of hypertext as a writer plus reader phenomenon. The role of semantic nets is described within the context of both the writer and the reader, and the relevance of hypertext techniques to computer software and expert systems is discussed. (42…