1 kaj grønbækcollaborative hypermedia collaborative hypermedia kaj grønbæk intermedia - Århus...
Post on 15-Jan-2016
223 Views
Preview:
TRANSCRIPT
1 Kaj GrønbækCollaborative Hypermedia
Collaborative hypermedia
Kaj Grønbæk
InterMedia - Århus
Aarhus University
kgronbak@intermedia.au.dk
2 Kaj GrønbækCollaborative Hypermedia
Plan
What is collaborative hypermedia
Classical hypermedia systems supporting collaboration
Collaboration support and the Web
Open hypermedia - collaboration support for the web
Advanced structuring mechanisms
Future directions and conclusion
3 Kaj GrønbækCollaborative Hypermedia
Collaborative hypermedia
Support for sharing and coordination of work with multimedia information• content as well as hypermedia structures
Both asynchronous and synchronous collaboration support• range from plain sharing of webpages to online shared editing
Different modes of collaboration• uncoupled, loosely coupled, tightly coupled, ...
Concurrency control• transactions, locking, etc.
Access control• who are allowed to do what?
Event notification• users are notified about important events
Versionning• Content and structure history can be inspected
4 Kaj GrønbækCollaborative Hypermedia
Collaborative hypermedia - potential application domains
Examples:
Engineers and designers working with sketches, drawings, and documentation
Supervisors, journalists, teachers etc., who digest and communicate material made by others
Digital libraries and museums used by researchers and students for their projects
Communities and non-governmental organisations who collect, and discuss various bodies of information
5 Kaj GrønbækCollaborative Hypermedia
Collaboration support in early hypermedia systems
NLS/Augment• Stanford Research Centre 1960’ies
KMS• CMU (ZOG) and Knowledge Systems Inc. (KMS) in the 1980’ies
Intermedia• Brown University in the 1980’ies
EHTS• Emacs HyperText System, Aalborg University, 1989-91
SEPIA• GMD-IPSI, Darmstadt, early 1990’ies
Devise Hypermedia (DHM)• Aarhus University, early 1990’ies
6 Kaj GrønbækCollaborative Hypermedia
Collaboration support in NLS/Augment
Electrionic mail• supports mailing of Augment documents
Journalization system for mail • documents frosen and stored in shared database
Shared screens and desktop conferencing• entire screen can be replicated to other users
• parallel phone connection for communikation
• control over documents can be transferred between users
http://www.csdl.tamu.edu/~leggett/engelbart.html
7 Kaj GrønbækCollaborative Hypermedia
Collaboration support in KMS
Multiple users can edit the same frameset and even the same frame (approx on page of text/graphics)
optimistic concurrency control to avoid locking
when conflicts occur the first who saves win, the rest have to save copies
frame owner can protect a frame from editing
transparent annotation items which do not print
Versionning• hierarchy (e.g. a paper) can “freezes” into a version
• when a frosen frame is being edited a new copy is created automatically
• action programs can be used to process versions
8 Kaj GrønbækCollaborative Hypermedia
Collaboration support in Intermedia
Intermedia Web = a collection of links and blocks• link and block information stored separat from content
• webs are stored in a conventional database
• easy to change context
• same document can be used in many contexts, i.e. many webs
Collaboration• multiple users can create and follow links in the same web
• read, write and annotation rights
• annotation means that you can link to the document but not modify it
9 Kaj GrønbækCollaborative Hypermedia
EHTS (Aalborg University)
General hypertext-based multiuser editing system• client-server system
• database server, text editor client, graphical browser client
”Relaxed” WYSIWIS user interface• placement of windows
• browser layout
• content update
Concurrency control
Event notification
Access control
10 Kaj GrønbækCollaborative Hypermedia
Collaboration in SEPIA
Similar to EHTS• locking, events, graphical browser
Seamless transition between different modes for collaboration:• uncouples mode: work on separate parts of shared material
• loosely-coupled mode: “awareness notifications”, handles conflicts and coordinering
• tightly-coupled mode: synchronous collaboration, shared environment
11 Kaj GrønbækCollaborative Hypermedia
Communication
User's workstation
Application A
ApplicationB
Browser
Hypermedia Service Process
Application Interfaces
Storage Classes
Runtime Classes
Application Layer
Layer
Storage Layer
(Physical)
RuntimeLayer
(Conceptual)
(WithinComponentLayer)
User's workstation
Application A
ApplicationB
Browser
Hypermedia Service Process
Application Interfaces
Storage Classes
Runtime Classes
ODHP
HypermediaDataBase server
(Storage Classes)HypermediaDataBase server
(Storage Classes)
ODHP
Document management system
Server host
Server host
Collaboration support in Devise Hypermedia (AU)
12 Kaj GrønbækCollaborative Hypermedia
Collaboration facilities
Event notifications:• Creation/modification/deletion of hypertexts
• Creation/modification/deletion of individual components
• Creation/modification/deletion of anchors
• Lock changes for entire hypertexts and components
• Users subscribe to event notifications for actions by: all users, a group of users, an individual user
• Users choose an update strategy: manual update, automatic (immediate update)
Session management
Long term transactions• locking
13 Kaj GrønbækCollaborative Hypermedia
Subscription
14 Kaj GrønbækCollaborative Hypermedia
Notification and refetch of components
15 Kaj GrønbækCollaborative Hypermedia
Change of lock for a component
16 Kaj GrønbækCollaborative Hypermedia
Barriers for collaboration support on the WWW per se
WWW is primarily a publicing medium
WWW do not allow users to create links from and into materials they do not own
WWW documents need to be modified to create links
WWW do not support user controlled organization of documents in other categories or hierarchies than those created by the author
WWW do not support coordination of collaboration on documents being worked on
17 Kaj GrønbækCollaborative Hypermedia
Tim Berners-Lee - the creator of WWW -about the future
Goal: Intercreative space As you can read, so can you write
If you notice a connection, make a link
Collaborative editing: research done, products nowhere?
Software hard
Needs authentication, PUT, catch lost update, version management, etc..
Amaya + Jigsaw progress
18 Kaj GrønbækCollaborative Hypermedia
Collaboration support on the Web
Shared repositories• BSCW (GMD)
• Lotus Notes/Domino
Annotation systems• ComMentor (Stanford)
• CritLink (www.critlink.org)
• ThirdVoice (www.thirdvoice.com)
Open Hypermedia• Microcosm/Webcosm (Southampton)
• Chimera (Boulder, Colorado)
• Webvise and Arakne (Aarhus University)
19 Kaj GrønbækCollaborative Hypermedia
Open hypermedia for the WWW
Users may create their own structures (links, collections, annotations etc.) on the Web
Structures stored in separate databases (contexts)
Many layers of structure on top of the same Web documents
Users may apply one or more layers at a time
Link object
I medfør af § 93, stk. 2 i bekendtgørelse nr. 1053 af 18. december 1995 om levnedsmiddelhygiejne og egenkontrol m.v. og § 20, stk. 2 i bekendtgørelse nr. 931 af 6. december 1995 om materialer og genstande bestemt til at komme i berøring med levnedsmidler fastsættes:
Ændringsbekendtgørelse nr. 1053 af 18. juli 1997 om .....
20 Kaj GrønbækCollaborative Hypermedia
Open hypermedia basis architecture
Collaboration on documents is coordinated by means of• Locking
• Event notification
• Versionning
A variety of modes for coupling users• Uncoupled
• Loosely coupled
• Tightly coupled
Web serverOffice apps.
Applications
StructureServer
Hyperstore
OHP
Office apps.Web Browsers
MS IE NS C
NavLets
Webvise
HSP
JDBC/ODBC
Proxy
Web server
21 Kaj GrønbækCollaborative Hypermedia
Component-based open hypermedia services
GeneralHypermedia
Database
GeneralHypermedia
Database
Navigationalservice
GeneralHypermedia
Database
Spatialservice
Annotational service
Taxonomicservice
Composite service
xxservice
NavLets
ApplicationsWeb Browsers
Open Hypermedia client
Office Apps
OHI
HDBI
22 Kaj GrønbækCollaborative Hypermedia
Webvise - open hypermediaclient application
Tailored for Internet Explorer via COM
23 Kaj GrønbækCollaborative Hypermedia
Demo
24 Kaj GrønbækCollaborative Hypermedia
Arakne: Includes support for multimedia linking
25 Kaj GrønbækCollaborative Hypermedia
The Arakne collaboration interface
Aim: support collaboration by providing shared awareness through a ‘low impact’ interface
Main interface components:• Session management
• Tickertape for notifications
• Subscription dialogs
Acknowledgement: N.O. Bouvin’s PhD project
26 Kaj GrønbækCollaborative Hypermedia
Examples of tightly coupled collaboration
Synchronised Web-browsing• Web-forum
• Distributed education
Collaborative authoring of web-news and journals• Production of a newsletter - on-line outline discussion
• Review and versionning of documents
Project work in education• Collaborative search, reflection and writing
27 Kaj GrønbækCollaborative Hypermedia
Examples of advanced open hypermedia services
”Well-known” services
Linking, annotations and guided tours
Developed recently
Linking in multimedia data on the Web - Mimicry
Spatial hypermedia
Typed links
28 Kaj GrønbækCollaborative Hypermedia
Arakne - Mimicry
Use the generic JavaMedia framework to present various media types
Proxy server replaces embeddings and links to movies, sounds etc. with a call of an applet
A controller applet provides the interface to selecting video segments
29 Kaj GrønbækCollaborative Hypermedia
Mimicry substitutes plug-in with its own media controller
30 Kaj GrønbækCollaborative Hypermedia
Link types in open hypermedia
Types are used to distinguish among links with different semantic meaning
Examples:
Teachers may use link types such as "introductory", "experienced", and "advanced" to distinguish sources based on the knowledge required to read them.
They may discuss the quality of the sources, by introducing link types such as "recommend as primary reading", "recommend as background reading", "useless" etc.
The teachers may use the type mechanisms to generate filtered browsers, e.g. with an overview of which of their subjects they have found "recommended primary readings" for
31 Kaj GrønbækCollaborative Hypermedia
Adding and visualizing linktypes in open hypermedia
32 Kaj GrønbækCollaborative Hypermedia
Spatial hypermedia
Relationships are implicit through proximity• Like stacks of paper on a desktop
Information analysis
Query postprocessing• Digital library application for students
• Sorting results of queries
33 Kaj GrønbækCollaborative Hypermedia
Spatial hypermedia Interface
34 Kaj GrønbækCollaborative Hypermedia
36 Kaj GrønbækCollaborative Hypermedia
Manufaktur Architecture
Ext
erna
lA
ppli
cati
ons
Cli
ents
on
loca
l mac
hine
Net
wor
ked
Ser
vers
Per
sist
ent
Sto
rage
HM Client
DirectX3D
Manufaktur
HM Server
3D Manuf.Server?
MS Access
XML TCP/IP DCOM?
ODBC?
ActiveX COM
MIA PS
ODBC
37 Kaj GrønbækCollaborative Hypermedia
Collaborative Hypermedia:research issues
Developing a general extensible infrastructure• with built-in collaboration support
Open set of "structure servers"• each (conceptual) server provides a set of structural abstractions
• data model extensibility
Open set of behaviors• "plug-in" to structure servers
• provide structural computation (e.g. traversal semantics)
Provide distribution/scalability that matches Web usage
Web integration and easy access.• Use meta-data perspective on open hypermedia structures
top related