%M C.ECHT.94.1
%T Coexistence and Transformation of Informal and Formal Structures:
Requirements for More Flexible Hypermedia Systems
%S Papers
%A Haake, Jorg M.
%A Neuwirth, Christine M.
%A Streitz, Norbert A.
%B Proceedings of the ECHT'94 European Conference on Hypermedia Technologies
%D 1994-09-18
%P 1-12
%K Hypermedia interface, Information structures, Meeting support, Design space
for hypermedia systems, Flexibility
%* (c) Copyright 1994 Association for Computing Machinery
%W http://www.acm.org/pubs/articles/proceedings/hypertext/192757/p1-haake/p1-haake.pdf
%X In this paper, we argue that some tasks (e.g., meeting support) require more
flexible hypermedia systems and we describe a prototype hypermedia system,
DOLPHIN, that implements more flexibility.  As part of the argument, we present
a theoretical design space for information structuring systems and locate
existing hypertext systems within it.  The dimensions of the space highlight a
system's internal representation of structure and the user's actions in
creating structure.  Second, we describe an empirically derived range of
activities connected to conducting group meetings, including the pre- and
post-preparation phases, and argue that hypertext systems need to be more
flexible in order to support this range of activities.  Finally, we describe a
hypermedia prototype, DOLPHIN, which implements this kind of flexible support
for meetings.  DOLPHIN supports different degrees of formality (e.g.,
handwriting and sketches as well as typed nodes and links are supported),
coexistence of different structures (e.g., handwriting and sketches as well as
typed nodes and links are supported), coexistence of different structures
(e.g., handwriting and nodes can exist on the same page) and mutual
transformations between them (e.g., handwriting can be turned into nodes and
vice versa).

%M C.ECHT.94.13
%T VIKI: Spatial Hypertext Supporting Emergent Structure
%S Papers
%A Marshall, Catherine C.
%A Shipman, Frank M., III
%A Coombs, James H.
%B Proceedings of the ECHT'94 European Conference on Hypermedia Technologies
%D 1994-09-18
%P 13-23
%K Spatial hypertext, Emergent structure, Interpretation, Visual structure
recognition, Composites
%* (c) Copyright 1994 Association for Computing Machinery
%W http://www.acm.org/pubs/articles/proceedings/hypertext/192757/p13-marshall/p13-marshall.pdf
%X The emergent nature of structure is a crucial, but often ignored, constraint
on authoring hypertexts.  VIKI is a spatial hypertext system that supports the
emergent qualities of structure and the abstractions that guide its creation. 
We have found that a visual/spatial metaphor for hypertext allows people to
express the nuances of structure, especially ambiguous, partial, or emerging
structure, more easily.  VIKI supports interpretation of a collected body of
materials, a task that becomes increasingly important with the availability of
on-line information sources.  The tool's data model includes semi-structured
objects, collections that provide the basis for spatial navigation, and object
composites, all of which may evolve into types.  A spatial parser supports this
evolution and enhances user interaction with changing, visually apparent
organizations.

%M C.ECHT.94.24
%T Fixed or Fluid?  Document Stability and New Media
%S Papers
%A Levy, David M.
%B Proceedings of the ECHT'94 European Conference on Hypermedia Technologies
%D 1994-09-18
%P 24-31
%K Hypertext, Documents, Fixity, Fluidity
%* (c) Copyright 1994 Association for Computing Machinery
%W http://www.acm.org/pubs/articles/proceedings/hypertext/192757/p24-levy/p24-levy.pdf
%X One of the crucial properties of documents through the ages has been their
fixity.  The ability to mark surfaces in relatively stable ways has made it
possible for people distributed across space and time to see the same images
and thereby to have access to the same meanings or communicative intent. 
Today, however, with the increasing use of digital technologies, it is often
asserted that we are moving from the fixed world of paper documents to the
fluid world of digital documents.  In this paper I challenge this assertion,
arguing instead that all documents, regardless of medium, are fixed and fluid.
Thus, although paper documents do fix aspects of communication, they do (and
must) also change; and although digital documents are easily changeable, they
must also be capable of remaining fixed.  I make use of this analysis in two
ways: first, to examine the fixity and fluidity of hypertext; and second, to
critique Bolter's argument in Writing Space concerning the movement from "fixed
to fluid."

%M C.ECHT.94.32
%T Extending the Microcosm Model to a Distributed Environment
%S Papers
%A Hill, Gary
%A Hall, Wendy
%B Proceedings of the ECHT'94 European Conference on Hypermedia Technologies
%D 1994-09-18
%P 32-40
%K Open, Distributed, Hypertext, Microcosm
%* (c) Copyright 1994 Association for Computing Machinery
%W http://www.acm.org/pubs/articles/proceedings/hypertext/192757/p32-hill/p32-hill.pdf
%X In recent years, there has been significant growth in the use of computer
networks to support electronic delivery of information.  As the volume of
available information has grown, a need for powerful tools that can manage
access has arisen.  It has been suggested that hypertext techniques can provide
such a facility.
   The Microcosm system is a hypertext link service developed at the University
of Southampton.  The system is based upon a modular architecture which allows
the functionality of the system to be easily and dynamically extended.  This
paper describes the development of a distributed version of Microcosm based
upon this modular design.
   The distributed system described utilises the fine granularity of the
Microcosm model to support a wide range of possible configurations.  The system
also extends the document management facilities of Microcosm to allow
information stored by other information services to be incorporated.  The
result is a system that can apply Microcosm's open linking services to a wide
range of networked information.

%M C.ECHT.94.41
%T Light Hypermedia Link Services: A Study of Third Party Application
Integration
%S Papers
%A Davis, Hugh C.
%A Knight, Simon
%A Hall, Wendy
%B Proceedings of the ECHT'94 European Conference on Hypermedia Technologies
%D 1994-09-18
%P 41-50
%K Open hypermedia, Hypermedia link services, Integration, Microcosm
%* (c) Copyright 1994 Association for Computing Machinery
%W http://www.acm.org/pubs/articles/proceedings/hypertext/192757/p41-davis/p41-davis.pdf
%X Recently there has been a tendency for the research community to move away
from closed hypermedia systems, towards open hypermedia link services which
allow third parties to produce applications so that they are hypertext-enabled.
This paper explores the frontiers of this trend by examining the minimum
responsibility of an application to co-operate with the underlying link
service, and, in the limiting case where the application has not been enabled
in any way, it explores the properties and qualities of hypermedia systems that
can be produced.  A tool, the Universal Viewer, which allows the Microcosm
Hypermedia System to co-operate with applications which have not been enabled
is introduced and a case study is presented which demonstrates the
functionality that may be achieved using entirely third party applications,
most of which have not been enabled.

%M C.ECHT.94.51
%T Adding Networking to Hypertext: Can it be Done Transparently?
%S Papers
%A Brown, Peter
%B Proceedings of the ECHT'94 European Conference on Hypermedia Technologies
%D 1994-09-18
%P 51-58
%K Wide-area network, Storage, Link, File, Active document, Distributed
hyperdocument, GUIDE
%* (c) Copyright 1994 Association for Computing Machinery
%W http://www.acm.org/pubs/articles/proceedings/hypertext/192757/p51-brown/p51-brown.pdf
%X Networks are becoming increasingly available and hypertext systems with
networking capabilities are currently enjoying exponential growth.  The vast
majority of hypertext systems were not, however, designed to cater for
networking.  This paper examines whether it is possible to add networking to
such systems and, if so, whether it can be done without upsetting existing
hyperdocuments, existing authors and existing readers.  The examination is done
using one specific hypertext system, UNIX Guide, but the lessons are, I hope,
more general.

%M C.ECHT.94.59
%T Composites in a Dexter-Based Hypermedia Framework
%S Papers
%A Grønbæk, Kaj
%B Proceedings of the ECHT'94 European Conference on Hypermedia Technologies
%D 1994-09-18
%P 59-69
%K Composites, Structure, Hierarchies, GuidedTour, Dexter model, Object
oriented framework
%* (c) Copyright 1994 Association for Computing Machinery
%W http://www.acm.org/pubs/articles/proceedings/hypertext/192757/p59-gronbaek/p59-gronbaek.pdf
%X This paper discusses the design and use of a generic composite mechanism in
the object oriented DEVISE Hypermedia (DHM) development framework.  The DHM
framework is based on the Dexter Hypertext Reference Model, which introduces a
notion of composite to model editors with complex or multiple types of
contents.  The original Dexter notion of composites is, however, insufficient
to cover structural composites including or referencing other components.  Thus
the DHM framework has been extended with generic composite classes suited to
support structures within the hypermedia network itself.  The paper presents
and discusses the design of the generic composite classes belonging to the
STORAGE and RUNTIME layers of the framework.  A central aspect of the design is
that the structuring mechanism is a true composite with a collection of
components as its contents rather than an atomic component with links to other
components as in the classical systems such as NoteCards, Intermedia, and KMS.
It is also shown how the powerful generic classes can be used to implement a
variety of useful hypermedia concepts such as: hierarchy by inclusion,
hierarchy by reference, virtual and computed browsers, TableTops and
GuidedTours.

%M C.ECHT.94.70
%T Adding Multimedia Collections to the Dexter Model
%S Papers
%A Garzotto, Franca
%A Mainetti, Luca
%A Paolini, Paolo
%B Proceedings of the ECHT'94 European Conference on Hypermedia Technologies
%D 1994-09-18
%P 70-80
%K Dexter model, Composite, Hypermedia design, Collection, Guided tour, Active
media
%* (c) Copyright 1994 Association for Computing Machinery
%W http://www.acm.org/pubs/articles/proceedings/hypertext/192757/p70-garzotto/p70-garzotto.pdf
%X The Dexter Model defines the notion of atomic components and composite
components, but it does not prescribe, nor it suggests, any particular
structure for composite components.  This paper proposes a specific type of
composite component, called "collection".
   A collection is a container holding several members.  Collections can
contain other collections (nested collections).  Collections can be regarded as
sets, but they can also have an inner structure.  Collections can be created in
several ways: manually, through queries, by operations on other collections, by
exploiting links, etc.
   Collections introduce a navigational pattern, based on their structure, that
is different from the standard node&link navigation.
   If active media are considered, collections allow the design and
implementation of complex synchronisation strategies, difficult to obtain
otherwise.
   The paper describes the motivations for using collections, their structure,
their navigational capabilities and a number of possible authoring mechanisms.
It also examines the interplay between standard navigation and collection
navigation, possible synchronization strategies for collections, as well as the
requirements for the definition of a runtime support (which could be used to
extend the runtime layer of the Dexter Model).

%M C.ECHT.94.81
%T Under CoVer: The Implementation of a Contextual Version Server for Hypertext
Applications
%S Papers
%A Haake, Anja
%B Proceedings of the ECHT'94 European Conference on Hypermedia Technologies
%D 1994-09-18
%P 81-93
%K Versioning, Alternatives, State-oriented versioning, Task-oriented
versioning, Implementation techniques, Publishing applications
%* (c) Copyright 1994 Association for Computing Machinery
%W http://www.acm.org/pubs/articles/proceedings/hypertext/192757/p81-haake/p81-haake.pdf
%X At GMD-IPSI we are developing CoVer, a contextual version server for
hypertext applications [11].  Another characterization of CoVer is that CoVer
integrates state-oriented versioning concepts with task-oriented versioning
concepts.  While other version models in general support only one of these
groups of concepts, we argue that the explicit composition of versions of
complex hypertext networks has to be complemented by automatic version creation
in the context of tasks or jobs performed while manipulating the hypertext
network and vice versa.  Regarding the implementation of version models, it
turns out that the state-oriented implementation approach -- representing every
legal state of a hyperdocument explicitly -- and the task-oriented
implementation approach -- computing versions of complex hypertext networks due
to changes executed during a task or job -- are interchangeable.  While the
separation of state- and task-oriented concepts at the conceptual level of the
version model is desireable to support version creation and selection for
different hypertext applications, the implementation of such a dual model can
be based on a single implementation approach.  This paper discusses both types
of implementation with an emphasis to cope with alternative versions that are
in particular meaningful for hypertext publishing applications.

%M C.ECHT.94.94
%T Chimera: Hypertext for Heterogeneous Software Environments
%S Papers
%A Anderson, Kenneth M.
%A Taylor, Richard N.
%A Whitehead, E. James, Jr.
%B Proceedings of the ECHT'94 European Conference on Hypermedia Technologies
%D 1994-09-18
%P 94-107
%K Multimedia information systems, Software engineering, Tools and techniques,
Document preparation, Hypertext/hypermedia, Design, Experimentation,
Heterogeneous hypertext, Hypertext system architectures, Link servers,
Separation of concerns, Software development environments
%* (c) Copyright 1994 Association for Computing Machinery
%W http://www.acm.org/pubs/articles/proceedings/hypertext/192757/p94-anderson/p94-anderson.pdf
%X Emerging software development environments are characterized by
heterogeneity: they are composed of diverse object stores, user interfaces, and
tools.  This paper presents an approach for providing hypertext services in
this heterogeneous setting.  Central notions of the approach include the
following.  Anchors are established with respect to interactive views of
objects, rather than the objects themselves.  Composable, n-ary links can be
established between anchors on different views of objects stored in distinct
object bases.  Viewers (and objects) may be implemented in different
programming languages afforded by a client-server architecture.  Multiple,
concurrently active viewers enable multimedia hypertext services.  The paper
describes the approach and presents an architecture which supports it. 
Experience with the Chimera prototype and its relationship to other systems is
described.

%M C.ECHT.94.108
%T SIROG -- A Responsive Hypertext Manual
%S Papers
%A Simon, Lothar
%A Erdmann, Jochen
%B Proceedings of the ECHT'94 European Conference on Hypermedia Technologies
%D 1994-09-18
%P 108-116
%K Hypertext manual, Situation-dependence, Task model, Process monitoring,
Process control
%* (c) Copyright 1994 Association for Computing Machinery
%W http://www.acm.org/pubs/articles/proceedings/hypertext/192757/p108-simon/p108-simon.pdf
%X Power plant operation and control in modern screen-based control rooms takes
place using computer displays which are directly coupled to the plant state. 
However, operators are provided with operational instructions and background
information by means of paper manuals or at best hypertext manuals with fixed
structure and contents.  Thus, information presentation is independent of the
current situation.
   To improve information accessibility we developed a situation-dependent
information medium: responsive manuals.  A responsive manual consists of a
"standard" hypertext-based operational manual and a task description.  It
monitors the changing situation and based on this is able to point to relevant
information.
   To show the advantages of the responsive manual approach in the domain of
power plant operation we implemented the SIROG (situation-related operational
guidance) system in close cooperation with Siemens.  It covers all parts of an
operational manual for accidents in a Siemens nuclear power plant, and is
coupled directly to the plant state.  The article discusses the basics of the
responsive manuals approach and the role of "responsiveness" in SIROG.

%M C.ECHT.94.117
%T Repertory Hypergrids: An Application to Clinical Practice Guidelines
%S Papers
%A Madigan, David
%A Chapman, C. Richard
%A Gavrin, Jonathan
%A Villumsen, Ole
%A Boose, John
%B Proceedings of the ECHT'94 European Conference on Hypermedia Technologies
%D 1994-09-18
%P 117-125
%K Implicit linking, Repertory grid, Clinical practice guidelines, Link
maintenance, Evaluation
%* (c) Copyright 1994 Association for Computing Machinery
%W http://www.acm.org/pubs/articles/proceedings/hypertext/192757/p117-madigan/p117-madigan.pdf
%X Creation and maintenance of links in large hypermedia documents is
difficult.  Motivated by an application to a federal clinical practice
guideline for cancer pain management, we have developed and evaluated a
repertory grid-based linking scheme we call repertory hypergrids.  Harnessing
established knowledge acquisition techniques, the repertory hypergrid assigns
each "knowledge chunk" a location in "context space".  A chunk links to another
chunk if they are both close in context space.
   To evaluate the scheme, we conducted a protocol analysis.  Six users of the
guideline addressing typical cancer pain management tasks made 30 explicit
links.  The repertory hypergrid using a neighborhood size of 16 captures 24 of
these links.  With optimization, the repertory hypergrid captures 27 of the
links with a neighborhood size of 13.

%M C.ECHT.94.126
%T Accessing Hyperdocuments through Interactive Dynamic Maps
%S Papers
%A Zizi, Mountaz
%A Beaudouin-Lafon, Michel
%B Proceedings of the ECHT'94 European Conference on Hypermedia Technologies
%D 1994-09-18
%P 126-135
%K Navigation, Maps, Information retrieval, Visualization, Interaction paradigm
%* (c) Copyright 1994 Association for Computing Machinery
%W http://www.acm.org/pubs/articles/proceedings/hypertext/192757/p126-zizi/p126-zizi.pdf
%X We propose a new navigation paradigm based on a spatial metaphor to help
users access and navigate within large sets of documents.  This metaphor is
implemented by a computer artifact called an Interactive Dynamic Map (IDM).  An
IDM plays a role similar to the role of a real map with respect to physical
space.  Two types of IDMs are computed from the documents: Topic IDMs represent
the semantic contents of a set of documents while Document IDMs visualize a
subset of documents such as those resulting from a query.  IDMs can be used for
navigating, browsing, and querying.  They can be made active, they can be
customized and they can be shared among users.  The article presents the
SHADOCS document retrieval system and describes the role, use and generation of
IDMs in SHADOCS.

%M C.ECHT.94.136
%T Interactive Clustering for Navigating in Hypermedia Systems
%S Papers
%A Mukherjea, Sougata
%A Foley, James D.
%A Hudson, Scott E.
%B Proceedings of the ECHT'94 European Conference on Hypermedia Technologies
%D 1994-09-18
%P 136-145
%K Navigation, Overview diagrams, Clustering, Information visualization
%* (c) Copyright 1994 Association for Computing Machinery
%W http://www.acm.org/pubs/articles/proceedings/hypertext/192757/p136-mukherjea/p136-mukherjea.pdf
%X This paper talks about clustering related nodes of an overview diagram to
reduce its complexity and size.  This is because although overview diagrams are
useful for helping the user to navigate in a hypermedia system, for any
real-world system these become too complicated and large to be really useful. 
Both structure-based and content-based clustering are used.  Since the nodes
can be related to each other in different ways, depending on the situation
different clustered views will be useful.  Hence, it should be possible to
interactively specify the clustering conditions and examine the resulting
views.  We present efficient clustering algorithms which can cluster the
information space in real-time.  We talk about the Navigational View Builder, a
tool that allows the interactive development of overview diagrams.  Finally, we
propose a 3-dimensional approach for visualizing these abstracted views.

%M C.ECHT.94.146
%T Frame-Axis Model for Automatic Information Organizing and Spatial Navigation
%S Papers
%A Masuda, Yoshihiro
%A Ishitobi, Yasuhiro
%A Ueda, Manabu
%B Proceedings of the ECHT'94 European Conference on Hypermedia Technologies
%D 1994-09-18
%P 146-157
%K Data model, Automatic linking, Spatial hypertext, Browsing, Visualization
%* (c) Copyright 1994 Association for Computing Machinery
%W http://www.acm.org/pubs/articles/proceedings/hypertext/192757/p146-masuda/p146-masuda.pdf
%X In taxonomic reasoning tasks, such as scientific research or decision
making, people gain insight and find new ideas through analysis of large
numbers of factual data or material documents, which are generally disorganized
and unstructured.  Hypermedia technology provides effective means of organizing
and browsing information with such nature.  However, for large amounts of
information, the conventional node-link model makes linking or browsing
operations be complicated because their relationship have to be represented as
binary relations.  In this paper, we propose a hypermedia data model call
Frame-Axis Model, which represents relationship between information as N-ary
relations on mapped space.  Also, the automatic information organizing
mechanism which is based on this data model and the browsing interface
HyperCharts which employ spatial layout are provided.  Finally, we show some
browsing examples on our working prototype system, CastingNet.

%M C.ECHT.94.158
%T Backtracking in a Multiple-Window Hypertext Environment
%S Papers
%A Bieber, Michael
%A Wan, Jiangling
%B Proceedings of the ECHT'94 European Conference on Hypermedia Technologies
%D 1994-09-18
%P 158-166
%K Hypertext, Hypermedia, Backtracking, Multiple window, History log, Session
log, Multiple pane
%* (c) Copyright 1994 Association for Computing Machinery
%W http://www.acm.org/pubs/articles/proceedings/hypertext/192757/p158-bieber/p158-bieber.pdf
%X Multi-window interfaces allow users to work on logically independent tasks
simultaneously in different sets of windows and to move among these logical
tasks at will (e.g., through selecting a window in a different task). 
Hypertext backtracking should be able to treat each logical task separately. 
Combining all traversals in a single chronological history log would violate
the user's mental model and cause disorientation.  In this paper we introduce
task-based backtracking, a technique for backtracking within the various
logical tasks a user may be working on at any given time.  We present a
preliminary algorithm for its implementation.  We also discuss several
ramifications of multi-window backtracking including the types of events
history logs must record, deleting nodes from history logs that appear in
multiple logical tasks, and in general the choices hypermedia designers face in
multi-window environments.

%M C.ECHT.94.167
%T An Interaction Engine for Rich Hypertexts
%S Papers
%A Østerbye, Kasper
%A Normark, Kurt
%B Proceedings of the ECHT'94 European Conference on Hypermedia Technologies
%D 1994-09-18
%P 167-176
%K Tailorability, Interaction engine, Aggregated views, Event control, Program
development
%* (c) Copyright 1994 Association for Computing Machinery
%W http://www.acm.org/pubs/articles/proceedings/hypertext/192757/p167-osterbye/p167-osterbye.pdf
%X In semantically rich hypertexts it is attractive to enable presentation of a
network of nodes and links at different levels of abstraction.  It is also
important that the user can interact with the hypertext using a command
repertoire that reflects the chosen abstraction level.  Based on a
characterization of rich hypertext we introduce the concept of an interaction
engine that governs the separation between internal hypertext representation
and external screen presentation.  This separation is the key principle of the
HyperPro system.  The HyperPro interaction engine is based on simple rules for
presentation, interpretation of events, and menu set up.  Much of the power of
the interaction engine framework comes from the organization of these rules
relative to the type hierarchy of nodes and links, and relative to a hierarchy
of so-called interaction schemes.  The primary application domain discussed in
the paper is program development and program documentation.

%M C.ECHT.94.177
%T The Hypermedia Authoring Research Toolkit (HART)
%S Papers
%A Robertson, John
%A Merkus, Erik
%A Ginige, Athula
%B Proceedings of the ECHT'94 European Conference on Hypermedia Technologies
%D 1994-09-18
%P 177-185
%K Hypertext, Hypermedia, Media-to-hypermedia authoring
%* (c) Copyright 1994 Association for Computing Machinery
%W http://www.acm.org/pubs/articles/proceedings/hypertext/192757/p177-robertson/p177-robertson.pdf
%X A major obstacle hindering the advancement and commercial acceptance of
hypermedia is the cost of converting paper based information into hypermedia
form.  The Hypermedia Authoring Research Toolkit (HART) was developed to
support the human editor during this media-to-hypermedia conversion process. 
The tool's goal is to help improve the correctness and completeness of the
hypermedia database, as well as reduce the media-to-hypermedia conversion cost.
   We believe it is not possible to properly convert media to hypermedia
without the participation of a human editor during the transformation.  It is
therefore necessary to develop tools to assist the human during this process. 
By reducing the overhead associated with the physical management of the
hyper-database construction, the subject specialist is better able to
concentrate on the information content.
   Support is provided in two basic ways:
 * By providing procedural guidance.  From our experience constructing
   hypermedia systems we have developed an efficient process for this
   media-to-hypermedia transformation.
 * By providing intelligent assistance.  At each phase in the transformation the
   system can suggest likely nodes, key phrases, index values, anchors, and
   links to the editor.
The project's research focus is to identify the most effective methodologies to
assist the human editor transform linear text, images and video into hypermedia
structure.

%M C.ECHT.94.186
%T Querying Structured Documents with Hypertext Links using OODBMS
%S Papers
%A Christophides, V.
%A Rizk, A.
%B Proceedings of the ECHT'94 European Conference on Hypermedia Technologies
%D 1994-09-18
%P 186-197
%K Structured documents, Hypertexts, Object oriented databases, Information
retrieval, Query languages, Path expressions
%* (c) Copyright 1994 Association for Computing Machinery
%W http://www.acm.org/pubs/articles/proceedings/hypertext/192757/p186-christophides/p186-christophides.pdf
%X Hierarchical logical structure and hypertext links are complementary and can
be combined to build more powerful document management systems [28,25,24,13]. 
Previous work exploits this complementarity for building better document
processors, browsers and editing tools, but not for building sophisticated
querying mechanisms.  Querying in hypertext has been a requirement since [19]
and has already been elaborated in many hypertext systems [11,7,4,21], but has
not yet been used for hypertext systems superimposed on an underlying
hierarchical logical structure.
   In this paper we use the model and the SQL-like query language of [10] in
order to manage structured documents with hypertext links.  The model
represents a structured document with typed links as a complex object, and uses
paths through the document structure, as first class citizens in formulating
queries.  Several examples of queries illustrate, from a practical point of
view, the expressive power of the language to retrieve documents, even without
exact knowledge of their structure in a simple and homogeneous fashion.  It
must be stressed that the proposed model and language implement the equivalent
HyTime [1] Location Address Module.  In fact, the language is more powerful
than the corresponding HyQ query facilities.  The implementation and the
description throughout the paper use the SGML standard [2] to represent the
document structure and the object-oriented DBMS O{sub:2} [12] to implement the
query language and the storage module.

%M C.ECHT.94.198
%T Querying Typed Hypertexts in Multicard/O2
%S Papers
%A Amann, Bernd
%A Scholl, Michel
%A Rizk, Antoine
%B Proceedings of the ECHT'94 European Conference on Hypermedia Technologies
%D 1994-09-18
%P 198-205
%K Hypertext querying, Browsing, Hypertext schema, Visual interface
%* (c) Copyright 1994 Association for Computing Machinery
%W http://www.acm.org/pubs/articles/proceedings/hypertext/192757/p198-amann/p198-amann.pdf
%X Due to the growing complexity of modern hypertext applications, current
hypertext systems require new mechanisms to support authoring and user
navigation through large sets of documents connected by links.  A general
solution is to extend hypertext systems to cater for semantics of application
domains.  This requires new hypertext models providing strongly typed documents
and links.  Such models have been proposed and put to use in systems such as
HDM and MacWeb to facilitate authoring of large hypertexts.  In addition, Gram
and MORE use typing and graph-based hypertext schemas for querying
hyperdocuments.  In this paper, we will show how query languages could be
further exploited for designing sophisticated general query-based navigation
mechanisms.  We illustrate our examples using the Gram model and describe an
implementation with the hypermedia system Multicard connected to the
object-oriented database management system O2.

%M C.ECHT.94.206
%T Where No Mind Has Gone Before: Ontological Design for Virtual Spaces
%S Papers
%A Kaplan, Nancy
%A Moulthrop, Stuart
%B Proceedings of the ECHT'94 European Conference on Hypermedia Technologies
%D 1994-09-18
%P 206-216
%K Spatial hypertext, Interface design, Information mapping, Navigation
%* (c) Copyright 1994 Association for Computing Machinery
%W http://www.acm.org/pubs/articles/proceedings/hypertext/192757/p206-kaplan/p206-kaplan.pdf
%X Hypermedia designers have tried to move beyond the directed graph concept,
which defines hypermedia structures as aggregations of nodes and links.  A
substantial body of work attempts to describe hypertexts in terms of extended
or global spaces.  According to this approach, nodes and links acquire meaning
in relation to the space in which they are deployed.  Some theory of space thus
becomes essential for any advance in hypermedia design; but the type of space
implied by electronic information systems, from hyperdocuments to "consensual
hallucinations," requires careful analysis.  Familiar metaphors drawn from
physics, architecture, and everyday experience have only limited descriptive or
explanatory value for this type of space.  As theorists of virtual reality
point out, new information systems demand an internal rather than an external
perspective.  This shift demands a more sophisticated approach to hypermedia
space, one that accounts both for stable design properties (architectonic
space) and for unforeseen outcomes, or what Winograd and Flores call
"breakdowns."  Following Wexelblat in cyberspace theory and Dillon, McKnight,
and Richardson in hypermedia theory, we call the domain of these outcomes
semantic space.  In two thought experiments, or brief exercises in interface
design, we attempt to reconcile these divergent notions of space within the
conceptual system of hypermedia.

%M C.ECHT.94.217
%T Aesthetic and Rhetorical Aspects of Linking Video in Hypermedia
%S Papers
%A Liestol, Gunnar
%B Proceedings of the ECHT'94 European Conference on Hypermedia Technologies
%D 1994-09-18
%P 217-223
%K Aesthetic, Rhetoric, Digital video, Media integration
%* (c) Copyright 1994 Association for Computing Machinery
%W http://www.acm.org/pubs/articles/proceedings/hypertext/192757/p217-liestol/p217-liestol.pdf
%X This paper reports on the development of a hypermedia environment for public
access in a museum.  It discusses problems encountered when making video
interactive and multilinear and when linking video and text in the creation of
the system.  Through the exchange of properties between print and video, media
approaches to linking and continuity are presented.  Visual examples are used
to illustrate this and related to the need to further develop aesthetic and
rhetorical aspects of linking video in hypermedia.

%M C.ECHT.94.224
%T Music in Time-Based Hypermedia
%S Technical Briefings
%A van Ossenbruggen, Jacco
%A Eliens, Anton
%B Proceedings of the ECHT'94 European Conference on Hypermedia Technologies
%D 1994-09-18
%P 224-227
%K Time-based hypermedia, Object oriented programming, Software sound synthesis
%* (c) Copyright 1994 Association for Computing Machinery
%W http://www.acm.org/pubs/articles/proceedings/hypertext/192757/p224-van_ossenbruggen/p224-van_ossenbruggen.pdf
%X The paper describes the extension of a hypermedia class library with music
as a new component type, but will focus on the development of a software
wrapper object as an application programmers interface to the Csound software
sound synthesis program.  This wrapper provides the flexible, interactive and
object oriented interface needed by a hypermedia system.  Additionally, some
consequences of the fundamental difference between static and time-based media
will be discussed.

%M C.ECHT.94.228
%T Experience with the Use of Acrobat in the CAJUN Publishing Project
%S Technical Briefings
%A Brailsford, David F.
%B Proceedings of the ECHT'94 European Conference on Hypermedia Technologies
%D 1994-09-18
%P 228-232
%* (c) Copyright 1994 Association for Computing Machinery
%W http://www.acm.org/pubs/articles/proceedings/hypertext/192757/p228-brailsford/p228-brailsford.pdf
%X Adobe's Acrobat software, released in June 1993, is based around a new
Portable Document Format (PDF) which offers the possibility of being able to
view and exchange electronic documents, independent of the originating
software, across a wide variety of supported hardware platforms (PC, Macintosh,
Sun UNIX etc.).
   The fact that Acrobat's imageable objects are rendered with full use of
Level 2 PostScript means that the most demanding requirements can be met in
terms of high-quality typography and device-independent colour.  These
qualities will be very desirable components in future multimedia and hypermedia
systems.  The current capabilities of Acrobat and PDF are described; in
particular the presence of hypertext links, bookmarks, and 'yellow sticker'
annotations (in release 1.0) together with article threads and multimedia
'plug-ins' in version 2.0.
   This article also describes the CAJUN project (CD-ROM Acrobat Journals Using
Networks) which has been investigating the automated placement of PDF
hypertextual features from various front-end text processing systems.  CAJUN
has also been experimenting with the dissemination of PDF over e-mail, via
World Wide Web and on CD-ROM.

%M C.ECHT.94.233
%T An Editor's Workbench for an Art History Reference Work
%S Technical Briefings
%A Rostek, Lothar
%A Mohr, Wiebke
%B Proceedings of the ECHT'94 European Conference on Hypermedia Technologies
%D 1994-09-18
%P 233-238
%K Editor's workbench, Hypermedia reference work, Knowledge-based system,
Object-oriented data modelling
%* (c) Copyright 1994 Association for Computing Machinery
%W http://www.acm.org/pubs/articles/proceedings/hypertext/192757/p233-rostek/p233-rostek.pdf
%X The architecture and some of the realized functionality of a prototype
Editor's Workbench that supports the creation and maintenance of an
object-oriented publisher's knowledge base is presented.  The knowledge base is
the repository not only for the actual publication content, but for all the
information needed to manage and control the publication process.  The concrete
application context is an art history reference work.  We discuss content
acquisition and data modelling aspects of the underlying object network.

%M C.ECHT.94.239
%T Representation and Manipulation of Conceptual, Temporal and Geographical
Knowledge in a Museum Hypermedia System
%S Technical Briefings
%A Taylor, Carl
%A Tudhope, Douglas
%A Beynon-Davies, Paul
%B Proceedings of the ECHT'94 European Conference on Hypermedia Technologies
%D 1994-09-18
%P 239-244
%K Knowledge based hypermedia, Museum information systems, Semantic modelling,
Temporal & geographical knowledge, Navigational aids, Semantic closeness
%* (c) Copyright 1994 Association for Computing Machinery
%W http://www.acm.org/pubs/articles/proceedings/hypertext/192757/p239-taylor/p239-taylor.pdf
%X This paper discusses a semantic database approach to museum hypermedia
systems based upon binary relations, with a restricted set of abstraction
relationships.  We describe examples of schema, queries and navigation aids for
a prototype system designed as a social history museum exhibit, with around one
hundred historical photographs.  Media items are classified according to
conceptual, temporal and geographical schema which attempt to model the
changing nature of geography over time.  The application yields a sparse
information space with densely populated clusters.  Implementations of notions
of semantic closeness, term generalisation, best fit solutions, media density
and media similarity show potential to assist the exploration of such
information spaces.

%M C.ECHT.94.245
%T HTML -- Poison or Panacea?
%S Panels
%A Glushko, Robert
%A Dougherty, Dale
%A Kimber, Eliot
%A Rizk, Antoine
%A Russell, Daniel
%A Summers, Kent
%B Proceedings of the ECHT'94 European Conference on Hypermedia Technologies
%D 1994-09-18
%P 245-246
%* (c) Copyright 1994 Association for Computing Machinery
%W http://www.acm.org/pubs/articles/proceedings/hypertext/192757/p245-glushko/p245-glushko.pdf
%X Many people are having their first experience with a distributed hypertext
system by using Mosaic or some other viewer based on HTML, the HyperText Markup
Language of the World Wide Web.  HTML's simplicity allows it to be created
without special authoring tools or expertise, and the ubiquity of free WWW
viewers like Mosaic removes one of the cost barriers.  Because HTML is an
application of SGML, the Standard Generalized Markup Language, it has also
introduced many people to the concepts and syntax of application-independent
markup.  The explosive growth of the WWW makes it undeniable that HTML and
Mosaic will serve as the reference point for much future thinking about
hypertext and SGML outside of the academic and research community.
   But if HTML is to some people a democratizing force for hypertext authoring
and publishing, to others its lack of structure and validation is a substantial
step backwards for authors, readers, and their organizations.  HTML has proven
the basic premise of SGML, that a standard, application-independent data
representation can enable blind interchange among disparate and even unknown or
unpredicted applications.  But to many SGML advocates, HTML is too primitive,
and today's HTML documents will end up as tomorrow's cast-off legacy data
format.  HTML viewers may seem appealing for network publishing, but to some
they are merely seductive and superficial, undermining years of careful
research on usability and business models.
   The goal of this panel is to de-balkanize the bi-polar HTML camps and seek a
productive role for all points of view.  HTML and the WWW are simply too
important for the academic and research community to ignore.  HTML will not go
away.  We must participate in the evolution of HTML and find ways to become
part of the network publishing revolution it represents.

%M C.ECHT.94.247
%T Does Multimedia Make a Difference?
%S Panels
%A Paolini, Paolo
%A Glushko, Robert
%A Dougherty, Dale
%A Kimber, Eliot
%A Rizk, Antoine
%A Russell, Daniel
%A Summers, Kent
%B Proceedings of the ECHT'94 European Conference on Hypermedia Technologies
%D 1994-09-18
%P 247
%* (c) Copyright 1994 Association for Computing Machinery
%W http://www.acm.org/pubs/articles/proceedings/hypertext/192757/p247-paolini/p247-paolini.pdf
%X Hypertext applications and tools in general deal with "passive" media. 
Values of passive media are static, in the sense that as time progresses their
presentation (state) does not change.  Values of active media have the property
of changing presentation (evolution of the state), as time progresses.  Active
media such as video, animation and sound are becoming a "necessity" in most
recent Hypertext applications.
   The panel discusses the impact of the introduction of active media in the
area of hypertext.  The impact of active media upon hypertext can involve
several aspects: presentation of the content, design of the applications,
structuring techniques of the applications, interplay between synchronization
and links, run-time support, communication performances and techniques for LAN
or WAN architectures.
   Panellists argue that:
 * Hypertext should remain well separated from Multimedia, being a separated
   field, with a different set of notions and needs;
 * A limited number of changes will be enough in order to adapt most of the
   Hypertext notions and techniques to multimedia;
 * A revolution is needed.

%M C.ECHT.94.248
%T CEC Briefing: Information Engineering and Telematics
%S Panels
%A Stevenson, Geoffrey
%A Holman, Lindsey
%A Adie, Chris
%A Minio, Roberto
%B Proceedings of the ECHT'94 European Conference on Hypermedia Technologies
%D 1994-09-18
%P 248-249
%* (c) Copyright 1994 Association for Computing Machinery
%W http://www.acm.org/pubs/articles/proceedings/hypertext/192757/p248-stevenson/p248-stevenson.pdf

%M C.ECHT.94.250
%T Private Sector Perspectives on Advances in Hypermedia
%S Panels
%A Nisen, W. G.
%A von Limback, Jeff
%A Johnson, Scott
%A Summers, Kent
%A Shephard, Maurice
%B Proceedings of the ECHT'94 European Conference on Hypermedia Technologies
%D 1994-09-18
%P 250
%* (c) Copyright 1994 Association for Computing Machinery
%W http://www.acm.org/pubs/articles/proceedings/hypertext/192757/p250-nisen/p250-nisen.pdf
%X Numerous market and industry segments are becoming increasingly interested
in hypermedia.  For example, hypermedia is a fundamental cornerstone in
electronic publishing, electronic performance support systems, and interactive
entertainment.  Most of the current state of the art in hypermedia is being
defined by research which is conducted in universities and research
institutions.  Yet many of the hypermedia systems that are in use today by
industry are first generation systems, often at least five years old.  This
begs the question: just how important is leading edge hypermedia technology to
the private sector?
   The areas that this panel addresses are:
 * Is there commercial rationalization for incorporating advanced hypermedia
   technology, and what is it?
 * How important is basic research and development in hypermedia technology to a
   company?
 * Is the current state of the art in hypermedia sufficient to successfully
   commercialize hypermedia products and services?
 * What are the best ways to transfer the results from hypermedia research from
   the academic and research communities to the private sector?