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Basic foilset Overview of Shared Places on the Web: XML for Web-based Collaboration and Distance Education

Given by Geoffrey C. Fox, Lukasz Beca, Marek Podgorny at XML Developers Conference Montreal on August 19-20 1999. Foils prepared August 21 99
Outside Index Summary of Material

We describe the essentials of shared event collaboration and how it is naturally integrated with the Web for both replicated client and server side shared objects.
We describe TangoInteractive and its applications
One use of XML is to define Shared Web Pages which implement both asynchronous (portal) and synchronous collaboration
Another use of XML is to support universal access and to link diverse display devices in collaborative sessions
We define the resultant event based architecture to be used in a new implementation of TangoInteractive

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1 Overview of Shared Places on the Web: XML for Web-based Collaboration and Distance Education http://www.gca.org/conf/xmldev99/ http://www.npac.syr.edu/users/gcf/montrealxmlaug99 XML Developers Conference Montreal August 19-20 1999
2 Abstract of XML and Collaboration
3 What is Web-based Collaboration?
4 Simplest Shared Object is Client Side Java Applet
5 Architecture of Tango Distance Education
6 So putting these ideas together for Distance Education
7 Applications of Web-based Collaboration
8 More General Shared server side Objects
9 Sharing Server Side Objects II
10 Shared Event Model of Collaboration?
11 So what do we have now--TangoInteractive
12 Next Generation TangoInteractive
13 Shared Places on the Web I
14 Shared Place Example: Introduction
15 Overview of Typical SPDL Document
16 SPDL Document Header
17 Declare the Shared Objects
18 What does SPDL Document Define
19 What SPDL Document Defines- continued
20 Definition of Groups of Users
21 Shared Places on the Web II
22 A Collection of Shared Place Components
23 Web Page with 2 Shared Objects
24 Collaboration Framework I
25 Each Collaborating Client Receives Events
26 SPW and Portals
27 SPW as Shared Portal on the Web
28 Two Uses of XML in Collaboration?
29 JSSB Currently Shares Existing Web DOM in Netscape 4.5
30 JavaScript Shared Browser with Dynamic HTML -- Shared Pointer
31 Shared Form Illustrated by Shared Access to NCSA Biology Workbench showing how general server objects can be shared from web interface
32 User and System Events
33 JSSB and Shared Card Games
34 Sharing XML Content Pages
35 XML JSSB Architecture
36 Applications of Shared XML Content Pages
37 XML and Universal Access I
38 XML and Universal Access II
39 Some Technical and System Comments
40 Conclusions

Outside Index Summary of Material

HTML version of Basic Foils prepared August 21 99

Foil 1 Overview of Shared Places on the Web: XML for Web-based Collaboration and Distance Education http://www.gca.org/conf/xmldev99/ http://www.npac.syr.edu/users/gcf/montrealxmlaug99 XML Developers Conference Montreal August 19-20 1999

From Overview of Shared Places on the Web XML Developers Conference Montreal -- August 19-20 1999. *
Full HTML Index
NPAC
111 College Place
Syracuse NY 13244 4100
Phone: 3154432163
Lukasz Beca
Geoffrey Fox
Marek Podgorny
Syracuse University
HTML version of Basic Foils prepared August 21 99

Foil 2 Abstract of XML and Collaboration

From Overview of Shared Places on the Web XML Developers Conference Montreal -- August 19-20 1999. *
Full HTML Index
We describe the essentials of shared event collaboration and how it is naturally integrated with the Web for both replicated client and server side shared objects.
We describe TangoInteractive and its applications
One use of XML is to define Shared Web Pages which implement both asynchronous (portal) and synchronous collaboration
Another use of XML is to support universal access and to link diverse display devices in collaborative sessions
We define the resultant event based architecture to be used in a new implementation of TangoInteractive
HTML version of Basic Foils prepared August 21 99

Foil 3 What is Web-based Collaboration?

From Overview of Shared Places on the Web XML Developers Conference Montreal -- August 19-20 1999. *
Full HTML Index
Collaboration means sharing objects
Web-based Collaboration implies use of Web to share distributed objects accessible through the Web
  • Shared Web Pages; Resources accessed through Web Servers or Brokers; Client-side applications with programmatic interfaces
Specify Page
Receive Identical Page
Web Site
HTML version of Basic Foils prepared August 21 99

Foil 4 Simplest Shared Object is Client Side Java Applet

From Overview of Shared Places on the Web XML Developers Conference Montreal -- August 19-20 1999. *
Full HTML Index
Web Pages are an example where there is a single copy of an object; perhaps simpler is the replicated object model used in chat-rooms and more generally shared applets where sharing is maintaining consistent state of replicas
Server Shares Events
Java Chat Rooms (applications or applets). Share text typed by users
HTML version of Basic Foils prepared August 21 99

Foil 5 Architecture of Tango Distance Education

From Overview of Shared Places on the Web XML Developers Conference Montreal -- August 19-20 1999. *
Full HTML Index
NPAC Web Server
JSU Web Server
Java Tango Server
.......
Share URL's
Audio Video
Conferencing Chat Rooms
White Boards etc.
Address at JSU of Curriculum Page
Teacher's View of Curriculum Page
Student's View of Curriculum Page
Participants at JSU
Teacher/Lecturer at NPAC
.......
Java Sockets
HTTP
Java Control Clients
All Curricula placed on the Web
HTML version of Basic Foils prepared August 21 99

Foil 6 So putting these ideas together for Distance Education

From Overview of Shared Places on the Web XML Developers Conference Montreal -- August 19-20 1999. *
Full HTML Index
We have curricula authored in some fashion and placed on the Web -- it is shared by sharing specification of current Web Page
  • At simplest this is URL but also supported using JavaScript API and Shared Web Page Events are:
  • Shared Scrolling position
  • Shared Pointer as DHTML layer
We have shared client side C++ object -- the digital audio-video conferencing subsystem
We have several shared Java applets
  • One or more Chat rooms
  • Whiteboard
  • "Raised Hand" / Quiz applets for specialized teacher-student interactions
HTML version of Basic Foils prepared August 21 99

Foil 7 Applications of Web-based Collaboration

From Overview of Shared Places on the Web XML Developers Conference Montreal -- August 19-20 1999. *
Full HTML Index
Multi Player Games: Use Chat Rooms and digital VTC to establish context
  • Share Java, JavaScript, VRML etc. games
  • Tango has Card Games, Othello, Chess, Snakes and Ladders
Crisis Management: Again use general tools (including whiteboard) and add shared maps and multimedia situation reports
Command and Control: Military, Test and Evaluation -- any real time control of complex system
  • support distributed experts who can be on call remotely and shared object is visualization of test results
Collaborative Computing and Engineering: Here specialized shared objects are CAD, simulation and planning tools
Socializing .....
HTML version of Basic Foils prepared August 21 99

Foil 8 More General Shared server side Objects

From Overview of Shared Places on the Web XML Developers Conference Montreal -- August 19-20 1999. *
Full HTML Index
Web Page Sharing is a special case of sharing server side objects -- CGI Scripts, Databases, Object Repositories etc.
This can be done by sharing the Web specification of these objects which can be done client side without ANY change to basic object
This is sharing of client side interface (proxy) to server side object
Specify Object
Collaboration Server Shares Object Specification
Receive Identical Specification
Fetch Identical Objects
HTML version of Basic Foils prepared August 21 99

Foil 9 Sharing Server Side Objects II

From Overview of Shared Places on the Web XML Developers Conference Montreal -- August 19-20 1999. *
Full HTML Index
We have used the shared proxy notion to implement
  • Shared Browser
  • Shared Form to access Server side computation (NCSA Biology Workbench -- bunch of CGI scripts)
  • Shared access to Web-linked database
Server does not need to know about detail of
collaboration.
It is more efficient if it
caches information for
re-use.
Thus use custom data-base
caching or general
proxy server
HTML version of Basic Foils prepared August 21 99

Foil 10 Shared Event Model of Collaboration?

From Overview of Shared Places on the Web XML Developers Conference Montreal -- August 19-20 1999. *
Full HTML Index
So if all clients want exactly same view at all times, then the "shared event" model is a waste.
Might as well, just share the display produced on originating client (cf. Microsoft NetMeeting)
In fact, shared event typically enables each client to get the same view but instead one shares the object but has different presentation layers on each client
For instance, share a single XML document but apply different style sheets on each client
Again in command and control, basic application is a 3D map (Geographical Information System) but not so interested clients can present a simple 2D view
HTML version of Basic Foils prepared August 21 99

Foil 11 So what do we have now--TangoInteractive

From Overview of Shared Places on the Web XML Developers Conference Montreal -- August 19-20 1999. *
Full HTML Index
http://www.npac.syr.edu/tango
Largely Java system enabling collaboration between general client side objects
  • If client side object is a Server proxy, then this ruse enables sharing of server side objects
  • Has API for Java applet/application, C++, JavaScript
API Enables sharing of events in applications
  • This is just a fancy way of saying it forwards messages
API Enables applications to find out about participants
Currently ONLY deployed for Netscape version 4.5 as uses LiveConnect to connect JavaScript to Java
  • Internet Explorer version not fully debuggd
HTML version of Basic Foils prepared August 21 99

Foil 12 Next Generation TangoInteractive

From Overview of Shared Places on the Web XML Developers Conference Montreal -- August 19-20 1999. *
Full HTML Index
So let us imagine that we can redo all of this and assume that
  • The proxy ruse is correct and one does only need to share client side Web Pages
  • There are plenty of conventional web pages but full support for XML and W3C DOM in browsers
  • XML can be used for control pages and specialized pages such as those produced by web-linked databases and education portals
Collaboration implies sharing of electronic objects and is needed in Asynchronous and Synchronous modes
Asynchronous mode is MOST important (in all applications including distance education) and will be supported by run of the mill object web infrastructure
  • shared web pages and documents
  • electronic mail
Synchronous mode has important applications and not done fully by giants ...
HTML version of Basic Foils prepared August 21 99

Foil 13 Shared Places on the Web I

From Overview of Shared Places on the Web XML Developers Conference Montreal -- August 19-20 1999. *
Full HTML Index
Each "Shared Place on the Web" or SPW is a set of XML and HTML documents
An XML document defines the collaboration Structure -- who is allowed in "Shared Place"; what objects can be there; where they are stored
  • This replaces the suite of undocumented rigid policies in TangoInteractive as well as scattered configuration files
  • There is one such XML document for each type of SPW e.g. there would be distedtojacksonstate.xml or xmldevelopersconf.xml etc.
  • We have developed SPDL (Shared Place Definition Language) which is currently quite simple and is used in the SPW structure definition
HTML version of Basic Foils prepared August 21 99

Foil 14 Shared Place Example: Introduction

From Overview of Shared Places on the Web XML Developers Conference Montreal -- August 19-20 1999. *
Full HTML Index
In this example we define a simple shared place where the results of some scientific computations are available.
The place can be used also for discussion among collaborating scientists. The discussion is supported by two shared objects: chat and data viewer.
The chat can be used for the text based discussion about presented results.
The data viewer can be used for the graphical presentation of the results. The authors of the results (`creators') have access to the advanced functionality of the data viewer. (e.g. support of particular XML dialects) They can use this functionality to present their findings visually to the `observers'.
The shared place is defined by two documents. The presentation layer is described by the HTML document and the collaboration functionality is defined by the SPDL XML/XSL document.
HTML version of Basic Foils prepared August 21 99

Foil 15 Overview of Typical SPDL Document

From Overview of Shared Places on the Web XML Developers Conference Montreal -- August 19-20 1999. *
Full HTML Index
The SPDL document defines several collaboration aspects of the shared place.
The header defines the communication protocol used for contact with collaboration server. (could be CORBA or what have you)
Next, all the shared objects embedded in the shared place are enumerated.
The following fragments define the user groups that have access to the shared place, specific user roles, and types of the collaborative sessions that are established in the shared place.
Other fragments describe how the data visible by different users are synchronized and specify the sources of the content presented by the shared objects.
Note how some Shared Place properties (e.g. users and files) are useful in non-collaborative page mode and others support both synchronous and asynchronous collaboration
HTML version of Basic Foils prepared August 21 99

Foil 16 SPDL Document Header

From Overview of Shared Places on the Web XML Developers Conference Montreal -- August 19-20 1999. *
Full HTML Index
<?xml version="1.0"?>
<placedef>
<head>
<title>Result Presentation</title>
<protocol type="plain">
<server>kopernik.npac.syr.edu</server>
<port򘮓</port>
</protocol>
</head>
The Header contains the title of the place.
It also declares how the shared place communicates with the collaboration framework. (I.e. server in Tango language)
The plain client/server protocol is chosen here with the collaboration server running on the machine: kopernik.npac.syr.edu on the port: 5555.
Other protocols such as IIOP can be used as well.
Initialize shared place definition
HTML version of Basic Foils prepared August 21 99

Foil 17 Declare the Shared Objects

From Overview of Shared Places on the Web XML Developers Conference Montreal -- August 19-20 1999. *
Full HTML Index
<sharedobject name="viewer"/><location> http://www.npac.syr.edu/experiments/apps/viewer.jar
  • </location>
  • <width</width>
  • <height</height>
</shared_object>
<sharedobject name="chat">......</sharedobject>
This fragment describes shared objects that are used in the shared place.
  • Two shared objects are declared.
  • Other objects which are not declared here, will not be supported by the Shared Place Framework in the `Result Presentation' place (HTML Page).
HTML version of Basic Foils prepared August 21 99

Foil 18 What does SPDL Document Define

From Overview of Shared Places on the Web XML Developers Conference Montreal -- August 19-20 1999. *
Full HTML Index
Collaboration functionality:
Session management: Defines how the Shared Objects initiate or join collaborative sessions
Synchronization: Describes mechanisms for assuring the consistence of data observed by collaborating users
Control mechanisms: Defines how the behavior of Shared Objects can be controlled and how the state of the collaboration session can be accessed
Shared Object data:
Initial state: Defines how the Shared Object are initialized when they start running
Persistence: Describes whether and how the content of the collaborative session is stored
Content: Describes the data to be processed by Shared Objects during collaboration session
HTML version of Basic Foils prepared August 21 99

Foil 19 What SPDL Document Defines- continued

From Overview of Shared Places on the Web XML Developers Conference Montreal -- August 19-20 1999. *
Full HTML Index
Users:
Grouping: Defines user groups with possibility of assigning roles
User identity based configuration: It is possible to define different behavior of Shared Object depending on the user, user group or user role
Referencing Shared Objects:
Shared Object ID: SPDL uses Shared Object ID to define properties for specific Shared Object
Granularity: It is possible to define different behavior for individual Shared Objects, classes of Shared Objects or for the whole Shared Place
HTML version of Basic Foils prepared August 21 99

Foil 20 Definition of Groups of Users

From Overview of Shared Places on the Web XML Developers Conference Montreal -- August 19-20 1999. *
Full HTML Index
<groups>
<group name="syracuse">
<user>morgan</user>
<user>cheng</user>
</group>
<group name="boston">
<user>smith</user>
<user>johnson</user>
</group>
<group name="washington">
<user>anderson</user>
<user>brown</user>
</group>
</groups>
This fragment of the SPDL document defines user groups. Those groups are used in further sections of the SPDL document to define other properties of the shared place. Three user groups, each with two users, are defined: syracuse, boston and washington.
HTML version of Basic Foils prepared August 21 99

Foil 21 Shared Places on the Web II

From Overview of Shared Places on the Web XML Developers Conference Montreal -- August 19-20 1999. *
Full HTML Index
There are HTML documents defining shared places themselves; they instantiate particular objects and form presentation layer
  • There is an associated XSL style sheet which invokes necessary programmatic capabilities and interprets XML islands in HTML document. These islands are defined in SPDL
  • There can be many SPW's presentation layers with a given SPDL structure
  • This (HTML + Style sheet) combination replaces the current TangoInteractive "Control Applet"
We will re-use some existing client side Java as SP agent and control objects invoked from style sheets
The TangoInteractive Server can also be largely re-used
HTML version of Basic Foils prepared August 21 99

Foil 22 A Collection of Shared Place Components

From Overview of Shared Places on the Web XML Developers Conference Montreal -- August 19-20 1999. *
Full HTML Index
<placedef>
.
. .
</placedef>
SPDL document
Web browser
Regular content
Web page
Shared objects
So Web Page is defined as a set of Nodes
-- You choose which nodes (and their children)
that you wish to share and then events are exchanged
maintaining state consistency
HTML version of Basic Foils prepared August 21 99

Foil 23 Web Page with 2 Shared Objects

From Overview of Shared Places on the Web XML Developers Conference Montreal -- August 19-20 1999. *
Full HTML Index
<HTML>
<head><title>Page with the computation results</title></head>
<body>
<xml id="placeDocument" src="results.xml"></xml>
<xml id="chatDef">
<embedobject name="chat">
<location>http://www.npac.syr.edu/experiments/apps/chat.jar
</location ></embedobject></xml>
<xml id="viewerDef">
<embedobject name="viewer">
<location>http://www.npac.syr.edu/experiments/apps/viewer.jar
</location ></embedobject></xml>
<xml id="style" src="spdl.xsl"></xml>
SPDL Definitions Page
Style Sheet
Shared Objects
HTML version of Basic Foils prepared August 21 99

Foil 24 Collaboration Framework I

From Overview of Shared Places on the Web XML Developers Conference Montreal -- August 19-20 1999. *
Full HTML Index
Objects register and then define their state via a stream of events
Need to share (federate) events between domains (your PC and mine) whose event services are normally isolated
"Tango Server"
Clients which receive events which are either queued (asynchronous)
or processed synchronously
HTML version of Basic Foils prepared August 21 99

Foil 25 Each Collaborating Client Receives Events

From Overview of Shared Places on the Web XML Developers Conference Montreal -- August 19-20 1999. *
Full HTML Index
Event Stream becomes set of time stamped XML messages
  • Control Messages: e.g. New Participant Joined
  • Shared Object Definition/Update Messages (e.g. Page Scrolled by such and such amount done as XML serialization of JavaScript Event object)
One or More Shared Places
One or More Shared Places
.............
HTML version of Basic Foils prepared August 21 99

Foil 26 SPW and Portals

From Overview of Shared Places on the Web XML Developers Conference Montreal -- August 19-20 1999. *
Full HTML Index
There is a lot of interest in portals these days
We build Web-based computing environments which are portals to Supercomputers and Web-based education or portals to a virtual university
Merrill Lynch predicts that Enterprise Information portal market will be $15B by 2002
Portals are built (by us) as a customizable set of XML components ( e.g. Run a Particular Program or display thumbnail of the next web-page in lecture)
SPW's can be thought of as customizable collaborative portals which define both synchronous and asynchronous shared components
HTML version of Basic Foils prepared August 21 99

Foil 27 SPW as Shared Portal on the Web

From Overview of Shared Places on the Web XML Developers Conference Montreal -- August 19-20 1999. *
Full HTML Index
Electronic Mail and News Updates are just "events" which can be handed to viewer objects in an SPW
  • In synchronous collaboration, events are typically generated on a client and immediately shared with other clients
  • Asynchronous events typically are generated by a server (which offers persistent store) and transmitted to client
Integration of Synchronous and Asynchronous Events is essential in "Next Generation" TangoInteractive
Customization is available as you can choose which objects are in your SPW and you can define customization parameters such as area for which you want weather and which sports results should be displayed
Such customized portals are commonplace but SPDL has the advantage that it specifies both synchronous and asynchronous portal components.
HTML version of Basic Foils prepared August 21 99

Foil 28 Two Uses of XML in Collaboration?

From Overview of Shared Places on the Web XML Developers Conference Montreal -- August 19-20 1999. *
Full HTML Index
We have introduced XML used to define the nature of collaboration in terms of objects, clients, policies
We have discussed user customization in terms of portals
Consider the JavaScript Shared Browser (JSSB) in TangoInteractive
It is an example of collaborative content built around sharing events defined in Web Page
  • Difficulties with "version 4 DOM" as bugs and inconsistent or incomplete implementations
  • However it can be made to work very effectively
Here we discuss "content" Web pages and not the "Collaboration Definition" Web pages we discussed already
Remember that "shared event" Collaborative systems share the object and not its particular presentation layer on each client
HTML version of Basic Foils prepared August 21 99

Foil 29 JSSB Currently Shares Existing Web DOM in Netscape 4.5

From Overview of Shared Places on the Web XML Developers Conference Montreal -- August 19-20 1999. *
Full HTML Index
Clicks on form/link in layers or frames
Clicks on layers
mouseover and mouseout ...
Can veto default action on clicks or other events on nonmaster side
  • Don't know how to veto changes on nonmaster in Netscape4
Save Form Contents at any time
  • can reload any dump at any time
Resizing so all clients have same scaling
Scrolling
Sharing can be customized from dialog window
Download times to monitor bad networks at application level
JSSB does monitor client page to detect unwanted page changes (One can capture clicks on Page links but not on "back button" )
HTML version of Basic Foils prepared August 21 99

Foil 30 JavaScript Shared Browser with Dynamic HTML -- Shared Pointer

From Overview of Shared Places on the Web XML Developers Conference Montreal -- August 19-20 1999. *
Full HTML Index
Shared Pointer added to Internet Assistant PowerPoint on the Web
Illustrates sharing of Web Object Model internal to document
HTML version of Basic Foils prepared August 21 99

Foil 31 Shared Form Illustrated by Shared Access to NCSA Biology Workbench showing how general server objects can be shared from web interface

From Overview of Shared Places on the Web XML Developers Conference Montreal -- August 19-20 1999. *
Full HTML Index
Shared Multiple List
Shared Buttons
Shared Text field
Shared Checkbox
HTML version of Basic Foils prepared August 21 99

Foil 32 User and System Events

From Overview of Shared Places on the Web XML Developers Conference Montreal -- August 19-20 1999. *
Full HTML Index
One can either share raw system message (click event occurred) or higher level user event generated by JavaScript invoked by event
Note Netscape 4.5 does NOT allow you to generate a general event in a page
  • You can invoke "click" events on form elements but not so events associated with layers
  • You can parse JavaScript invoked by event and transmit but this is unreliable
So User events are convenient and sometimes required
Function process() ...
Invoke Tango JS Interface
with user defined meaning
Click on Button which happens to
invoke some User JavaScript Code
Capture Click and
Invoke Tango JS Interface
with meaning that click occurred
Or
HTML version of Basic Foils prepared August 21 99

Foil 33 JSSB and Shared Card Games

From Overview of Shared Places on the Web XML Developers Conference Montreal -- August 19-20 1999. *
Full HTML Index
Dialog Box Invokes Shared User Events
Cards are 56 DHTML Layers
All of this
implies XML
Framework
for Card Games
and Internet Gambling
HTML version of Basic Foils prepared August 21 99

Foil 34 Sharing XML Content Pages

From Overview of Shared Places on the Web XML Developers Conference Montreal -- August 19-20 1999. *
Full HTML Index
So "new version of JSSB" for SPW should implement:
  • Share XML content of a document
  • Allow each collaborating client to generate personalized presentation layer using customized stylesheet or equivalent
Note TangoInteractive can map object specification on each client and so customization can be performed either before or after web page generated
  • Currently we map URL's before submission so each client accesses optimal mirror site (if available)
HTML version of Basic Foils prepared August 21 99

Foil 35 XML JSSB Architecture

From Overview of Shared Places on the Web XML Developers Conference Montreal -- August 19-20 1999. *
Full HTML Index
Content Server
Shared by SPW
Events
Trapped by XML JSSB
Master
Nonmaster
HTML version of Basic Foils prepared August 21 99

Foil 36 Applications of Shared XML Content Pages

From Overview of Shared Places on the Web XML Developers Conference Montreal -- August 19-20 1999. *
Full HTML Index
Support of Collaboration between PC client, Palmtop and high graphics devices such as CAVE's
So in education, can support a mix of wireless palmtops and laptops in the class, with distance PC's
  • Laptops and PC's get all the information including shared PowerPoint/Web Curricula pages etc.
  • Palmtops just get quizzes, chatrooms, whiteboard etc.
Linkage of geographically distributed researchers is necessary to support collaborative computational science
  • One researcher may be in a 3D virtual environment
  • Others will be looking at traditional scientific visualization on workstations
A common XML specification of visualization is mapped according to display capabilities of client device
HTML version of Basic Foils prepared August 21 99

Foil 37 XML and Universal Access I

From Overview of Shared Places on the Web XML Developers Conference Montreal -- August 19-20 1999. *
Full HTML Index
It is essential that collaborative technologies support all users independent of their hardware and physical capabilities
Hardware issues are essentially illustrated by palmtop to CAVE example on previous foil
Suppose we wish to teach a class where some students and/or teachers have impaired sight and hearing.
Then we need to share same object content but render it differently on each client.
  • Possibly want to render a given object in multiple ways on a given machine
Essential to share content (as in XML JSSB) and this enables you to choose right presentation for given client
  • Typical HTML layout aimed at fully capable users and needs to be redone for physically impaired users
Concepts of XML JSSB for universal access developed with Al Gilman from Trace Center
HTML version of Basic Foils prepared August 21 99

Foil 38 XML and Universal Access II

From Overview of Shared Places on the Web XML Developers Conference Montreal -- August 19-20 1999. *
Full HTML Index
Assume that all education will be web-based
Assume that we need to provide web resources of equal quality for all citizens
This will not work if one has to translate each course from material for "regular user" to that for "user for different access capabilities"
Thus only chance is to define curriculum in XML and produce customized presentation layers
One will need a powerful indexing/abstracting scheme to be able design appropriate navigation schemes for all users and clients
  • Natural framework is XML based Education Portals with SPW implementing collaboration (a.k.a. teaching)
HTML version of Basic Foils prepared August 21 99

Foil 39 Some Technical and System Comments

From Overview of Shared Places on the Web XML Developers Conference Montreal -- August 19-20 1999. *
Full HTML Index
There is a lot of Tango Software lying around to implement collaboration and so natural to implement customization in Java or JavaScript as an alternative to XSL
  • 15,000 lines JavaScript and a lot more Java
Note JavaScript very fast but phenomenological
  • Undefined thread behaviour etc. makes for experimental programming
  • However there is usually way of getting things to work
Note that on detects events at presentation layer but must share at object layer -- only works if this connection well defined
XML Content
Pages
Events Trapped
by XML JSSB
define object state
Converted by Browser etc.
Shared Object
HTML version of Basic Foils prepared August 21 99

Foil 40 Conclusions

From Overview of Shared Places on the Web XML Developers Conference Montreal -- August 19-20 1999. *
Full HTML Index
We have analyzed a successful Web-based collaboration system TangoInteractive and in particular its JavaScript interface enabling shared interactive web pages
We have noted that it is very helpful to
  • use XML and new W3C DOM
  • Link Asynchronous and Synchronous events
  • Link Portal and Collaboration technology
XML can be used in defining portal/shared collaboration space
XML can support universal access to collaborative environments to those with disabilities -- hence giving them access to education
XML can support collaboration between clients from palmtops, to PC's and high-end virtual environments
TangoInteractive is available now at http://www.npac.syr.edu/tango
Prototypes involving SPDL and Collaborative PC's/palmtops will be available in Jan 00
This talk is: http://www.npac.syr.edu/users/gcf/montrealxmlaug99
© Northeast Parallel Architectures Center, Syracuse University, npac@npac.syr.edu

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