In this paper, we report about the design, development, and implementation of the SEPIA cooperative hypermedia authoring environment. It provides results on the following aspects of SEPIA: persistent and shared data storage, hypermedia data model with composites, sophisticated and comprehensive authoring functionality, support for a new rhetoric and for cooperative work. We start by identifying the challenge of hypermedia authoring and production which serves as the driving force for our development. Using interacting problem spaces as the vehicle for modelling the dynamic aspects of authoring, we arrive at a set of requirements answered by the concept of "activity spaces". The design of coherent hyperdocuments is facilitated by our "construction kit". Furthermore, we describe the extensions and modifications necessary to support multiple authors with the cooperative version of SEPIA. The central issue of the paper is the system architecture and its implementation. We describe the basi...

Hypertexts may be implicitly structured, based on either node content or context. In this paper, we examine implicit structures that rely on the interpretation of node’s spatial context. Hypertext authors and readers can perceive and understand these idiosyncratic structures, but, because they are implicit, they cannot be used by the system to support users ’ activities. We have explored spatially structured hypertext authored in three different systems, and have developed heuristic recognition algorithms based on the results of our analyses of the kinds of structures that people build. Our results indicate that (1) recognition of implicit structures in spatial hypertext is feasible, (2) interaction will be important in guiding such recognition, and (3) the hypertext system can provide layout facilities that will render later systematic interpretation much easier. Found structures can be used as a basis for supporting information management, as a straightforward way of promoting knowledge-base evolution, as a way of solving representational problems endemic to many hypertext systems, or as a basis for collaboration or interaction.

The hypermedia field has long realized the need for firstclass structural abstractions. However, we have failed to generalize the concept of ubiquitous structure management to problem domains other than navigation of information spaces. In this paper, we argue for the recognition of such a generalization, called structural computing, in which we assert the primacy of structure over data. We provide examples of four problem domains that are more naturally modeled with structure than data. We argue that support for structural computing must come in the form of new models, operating systems, and programming languages. We also assert that the experience gained by hypermedia researchers over the last decade may be naturally extended to form the basis of the new field of structural computing, and furthermore, the broadening of the applicability of our work is necessary for the continued vitality of our research community.

This work analyzes the central role of interpretation in non-routine design. Based on this analysis, a theory of computer support for interpretation in cooperative design is constructed. The theory is grounded in studies of design and interpretation. It is illustrated by mechanisms provided by a software substrate for computer-based design environments, applied to a sample task of lunar habitat design. Computer support of

Abstract: In the information age, lifelong learning and collaboration are essential aspects of most innovative work. Fortunately, the computer technology which drives the information explosion also has the potential to help individuals and groups to learn much of what they need to know on demand. In particular, applications on the Internet can be designed to capture knowledge as it is generated within a community of practice and to deliver relevant knowledge when it is useful. Computer-based design environments for skilled domain workers have recently graduated from research prototypes to commercial products, supporting the learning of individual designers. Such systems do not, however, adequately support the collaborative nature of work or the evolution of knowledge within communities of practice. If innovation is to be supported within collaborative efforts, these domain-oriented design environments (DODEs) must be extended to become collaborative information environments (CIEs), capable of providing effective community memories for managing information and learning within constantly evolving collaborative contexts. In particular, CIEs must provide functionality that facilitates the construction of new knowledge and the shared understanding necessary to use this knowledge

The historical development of hypermedia systems can be characterized as a series of successive abstractions of functionality away from the "core " hypermedia server, often resulting in a new open layer in the hypermedia environment architecture. Recently, this trend of abstraction has been applied to the hypermedia server itself, replacing the notion of a single, closed hypermedia server with an open layer of structure servers. This newest development brings with it a new set of challenges and research issues for open hypermedia researchers. In this paper, we discuss these issues, review some of our collective applicable experience with contemporary open hypermedia systems and other work, and point out some of the more pressing and intriguing open questions that we feel are facing open hypermedia researchers today. We also examine the "split" in the current hypermedia research community between "system " and "domain " researchers and the still-present need for interoperability among systems, and discuss why any attempt to address the issues we discuss in this paper must account for these observations.

Cooperative work typically involves both individual and group activities. Computer support for perspectives allows people to view and work in a central information repository within personal contexts. However, work in personal perspectives encourages divergent thinking. Negotiation in group perspectives is needed to converge on consensus, shared understanding, and cooperation. Negotiation processes on their own can delay progress. By intertwining perspective and negotiation mechanisms, individual results can be systematically merged into a group product while work continues. Personal perspectives on shared information are thereby intertwined and merged into a shared group understanding. WEBGUIDE is a prototype system that integrates perspective and negotiation mechanisms; its user interface has been mocked up in detail to work out the many issues involved. We have begun to use partial implementations of WEBGUIDE to support cooperative intellectual work in small research groups.

. Tailoring groupware has to deal with adapting properties of a shared information space as well as with adapting properties of the cooperation support to the group's needs. In this paper, an approach for tailoring both aspects of groupware in an integrated fashion is proposed. This approach uses cooperative hypermedia as a unifying representation of shared information structures, functionality, and the coordination medium of a shared application. It enables cooperative definition of shared information structures, shared process models and their access models not only before collaboration starts, but also on the fly, when emergent processes evolve. The proposed approach addresses tailoring at all stages of the development and use of a groupware application. A prototype system called CHIPS is presented and different possibilities of tailoring in CHIPS are discussed. Examples of CHIPS demonstrate that the cooperative hypermedia approach to tailoring groupware can support the adaptation ...

Activity spaces are usually task-specific and only common to a group of people who work together in a certain application domain. It is desirable to enable users to define and modify activity spaces according to their needs. However, many users are unable to use a pre-defined activity space correctly or incapable of formally defining an activity space. This work tries to solve these problems 1) by developing a flexible hypertext meta-model which can represent activity space semantics, 2) developing an example-based definition tool for users to create task-specific activity spaces, 3) providing intelligent aid in using these activity spaces, and 4) providing a flexible space for adopting existing and emergent patterns. A system (COWFISH) with the above components has been implemented and tested at GMD-IPSI. Examples and initial applications have shown that using the system users can easily define the schemata of many activity spaces and hyperdocuments. They can also create new activ...

In their contributions, participants of spatial planning discussions refer to geographic objects. In this paper, an explicit linkage between online maps and arguments is proposed for being used in a World-Wide Webbased support systems for Collaborative Spatial Decision-Making #CSDM#. The representation and storage of geo-referenced arguments in Argumentation Maps #"Argumaps"# will advance the level of integration and utility of asynchronous discussion forums and digital plans. Geographically distributed users involved in public planning debates will be able to query and analyze ongoing discussions and to submit constructive contributions. The paper summarizes related concepts of Argumentation Theory and Geographic Information Science, and describes a potential Argumap implementation based on two existing software tools for discussion and for mapping, respectively. Keywords: Argumentation Map, CSDM, planning discussions, GIS, World-Wide Web 1 Introduction Participants of spatial pla...