Transcript No Slide Title

A Distributed Open
Asynchronous Information
Access and Management
Environment
by
Mehmet Sen
EECS, Syracuse University
Advisor: Geoffrey C. Fox
November 30, 2000
7/18/2015
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Outline




Research & Problem Definition
Some Contributions
Related Work (Standardization efforts,…)
A Software Architecture



Middle-tier Services
Front-tier Interfaces
Related security issues
 Issues of proposed distributed system
 Summary of Contributions
 Conclusions
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What Is Our Research?
 Designing: a multi-tier architecture for
commodity computing.
 Studying: the basic needs for a learning
management system (LMS).
 Applying: our design as a LMS.
 Analyzing: the results both from building
the architecture and from practical usage.
 Proposing: a new computing framework
model based on our lessons.
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Motivations
Why are we doing this research?
 Learning technologies are improved in last halfdecade as well as technologies in other fields.
 Commodity technologies are shaping learning
technologies. (Complete web-based learning
environments).
Technology
applications in
learning
Prior to 1998
Primitive applications
of technology
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1999
Widespread
Technology Tries
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STANDARDS
APPEARING
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Basic Needs and Problems Encountered
Leading to Our Research:
 Distance learning: difficulties that off-campus geographically
distributed students have in following a web-based course.
 Providing a complete on-line course environment
for on-campus students: benefits of keeping student records in a
trustable, easily-securely accessible database environment
 Technical overload of web course preparation: lists,
accounts, home pages, add-drop, surveys many hours of human effort because of
no automated environment.
 Grading with distributed teaching teams.
 Online progress tracking: Online grading, surveys and quizzes,
on-the-fly
etc.
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Need for Further Research
Why do we need to research, is there difference?
 This area (educational technologies) is in its
infancy, we do not have yet next generation
sophisticated web-based learning environments.
 There is a collapse to construct fundamentals on
an educational architecture, or computing
architecture between educators and computer
scientists.
 We are not expert in education research, but it
seems that technical architectures are weak, i.e.,
old.
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Major Contributions
 Scientific and architectural view of asynchronous support in
distance education.
 The multi-tier architecture model for a distributed, open,
asynchronous information access and management environment.
 Artifact: architecture’s prototype: virtual classroom manager
(VCM.).
 Lessons learnt and further/future research.
 A new computing framework model based on our
lessons.
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A Compact Taxonomy of
Learning Technologies
 Content preparation
 Content delivery:


Asynchronous
Synchronous
 Information management
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Advances in Learning Systems
What is done as learning systems?
 Development of academic and commercial sources


WebCT, Blackboard, Lotus Learning Space, WebMC …
(mainly interesting as authoring strategy)
Tango, WebEx, Centra, Placeware (delivery)
 Standardization Efforts: (examples)


IMS (Instructional Management Systems)
DoD; ADL (Advanced Distributed Learning ), AICC
(Aviation Industry CBT Committee)
 IEEE LTSC (Learning Technology Standards
Committee)
 ARIADNE (Alliance of Remote Instructional Authoring
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& Distribution Networks
for Europe)
IEEE LTSA (architecture)
by Learning Technology Systems Consortium (LTSC)
Learner
Entity
Multimedia
Delivery
Interaction Context
Loc
ato
VCM
Evaluation
Learning
Preferences
r
Learning Locator
Content
Catalog Info
Learning
Resources
Query
Behavior
Coach
e
s
s
A
e
ssm
nt
Performance
(current)
(history/obj.)
Learner
Performance/
Preferences
Records
(new)
•framework for general learning technology systems (to understand sys.)
•Neutral, promotes interoperability in 5-10 years
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Traditional classroom mapped to LTSA
system components
Learner
Multimedia
Delivery
Behavior
Learning Content
Loc
Evaluation
Learning
Style
r In
Learning
dex
Content Content Index
(metadata)
System
Knowledge
Coach
Library
Query Index
ato
ent
m
ess
s
s
Performance
A
(current)
Performance
(history)
Records
Database
Performance (new)
Abstraction
Implementation
Student
Student Uses
Library
Teacher Points Student To
Books (A Locator Index)
School
Library
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Teacher
Grades
Report
Cards,
Transcript
Retrieves Teaching Materials
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VCM mapped to
LTSA system components
Learner
Multimedia
Behavior
Learning Content
Delivery
Loc
Learning
r In
Style
Learning
d ex
Content Content Index
(metadat a)
System
Knowledge
Coach
Library
Query Index
at o
A ss
e ss
m
Evaluation
en t
Performance
(history)
Performance
(current)
Performance (new)
Records
Database

Abstraction

Implementation
Student
Takes quizzes,
Fills out surveys
Learns results
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Quiz &
Assgnmnt
Library
Teacher
Presentation
tool
(browser)
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Enters quiz materials and
assignment grades
Retrieves results &
statistics
Report
Cards,
Transcript
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How Do Standards Come Alive?
IEEE, ANSI, ISO: Accredited Standards
LTSC
(P1484)
Liaison
Liaison
Liaison
Education & Learning Technology Orgs: AICC, ADL, IMS, ARIADNE
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Standardization Efforts in
Learning Technologies I
 Course content preparation;






SCORM (Sharable Courseware Object Reference Model) by DoD
ADL (Advanced Distributed Learning)(1/00)
Content Packaging by IMS (Instructional Management Systems)
(2/00)
Content Management by IMS (just starting)
LRN (Learning Resource Interchange) by The Microsoft (01/00)
Content Play Rules [Ostyn]
UFI Content Interworking Schema [FD-UFI]
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Standardization Efforts in
Learning Technologies II
 Metadata:


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IMS Metadata for describing learning resources
IEEE LOM Learning Object Metadata
describes learning content cataloging
information (basically proposed by IMS and
ARIADNE)
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Standardization Efforts in
Learning Technologies III
 Evaluation & Assessment;

IMS Question and Test Interoperability Specification
(/00) (provides proposed-standard XML language for describing
questions and tests. )
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Standardization Efforts in
Learning Technologies V
 Human Information Management

Public and Private Information (PAPI) for Learners Draft
Standard for Learning Technology (previously known as
Personal and Performance Information)
• Logical categories of learner information
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Further Organizations
 PROMETEUS (PROmoting Multimedia Access to Education and
Training in EUropean Society)
 The Dublin Core:





Metadata for discovering Electronic Resources
author-generated description of Web resources,
Simplicity + Semantic Interoperability+International
Consensus+Extensibility
Metadata Modularity on the Web: The World Wide Web Consortium (W3C)
works on architecture for metadata on the Web.
The Dublin Core's Resource Description Framework (RDF) is for different
metadata needs of vendors and information providers.
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Open Standards & Technologies





HTML, DHTML, JavaScript, JSP
XML, XSL, RDF, DOM, SAX
Java, Servlets,
HTTP, IIOP, COM
DCOM, CORBA, EJB, RMI
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Open technologies & Learning
Standards
 Will(may) provide us:



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Integration of leading systems in one big
environment
Easy management of systems
Rich set of properties such as discoverability,
accessibility, interoperability, reusability,
durability, extensibility, quality, modularity,
simplicity, etc.
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What Standards and Current
Practices Miss ?
 Well designed architectures
 Some standards or models may dependent
on current practices’ scope.
 Some standards or models may not be longlasting (or equivalently problematic in long
term)
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Our Multi-Tier Architectures
Our very first short termed architecture
HTML+JavaScript
OWA, or
WOW+wowstub
Database
Bridge
Web
Server
Database
Connection
script
Database
client
Oracle Web Server
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Current architecture
Legacy
Systems
System
Manager
Web
Server
Services
Legacy Bridge
High
Level
Object
Object
Request Providers
Brokers
Database
Bridge
client
Database
Database
Bridge
Database
Bridge
Database
Bridge
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Database
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Database
Database
WO
Represents Web Object
System
Manager
Web
Server
Legacy
Systems
WO
High
Level
Object
Object
Providers
Request
Services Brokers
Legacy Bridge
Database
Bridge
WO
WO
Database
Web
Object
Web
Object
Web
Object
System
Manager
Web
Server
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High
Level
Object
Object
Providers
Request
Services Brokers
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Database
Bridge
Database
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Multi-Tier Architecture(implementation view)
Client
Frustrated Evil
People
Access Logs
CGI
Module
Client
Client
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11/2/2000
JAVA OBJECTS
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Template
Library
Object Brokers
128 Bit Secure
Socket Layer
Servlets
Parser
Module
CACHE Modules
Client
Secure
Web
Server
High
Level
Request
Services
Legacy
Systems
Object
Providers
Database
JDBC Records
Oracle,mSQL
HTTP, IIOP, RMI,
DCOM, TCP/IP Socket
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Issues on Web Objects
 There are various common object models,
like COM, CORBA, Java, Web, etc..
 Choosing an implementation model is not
important as long as XML is the language to
communicate between systems.
 We preferred a Web Object Model, served
as XML documents on the Web
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DB to WEB With XML
(Object Service View)
HTTP, IIOP,
RMI, DCOM,
TCP/IP Socket
JDBC
DB
Web
Server
DOM
Object
Provider,
Broker
Request
Services
Servlets
XSL
Templates
HTTP
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Features of VCM

Multi-tier architecture

Commodity user interfaces, and administration.

Asynchronous collaboration of users, e.g.,
• supervisors, instructors, co-instructors, TAs, students, guests, and administrators

Security mechanisms;
• SSL, user authentication, access privileges, ACL, browser protections, etc.

Virtual university records for
• students,
• courses,
• Assignments
• Faculty,
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Features of VCM II

Assessment tools: online grading, online surveys,
statistics, etc.

Virtual university services, e.G.,
• Online course registration, post-office & automated mail lists, password assignment,
file uploading, class lists, surveys, quizzes, grades, performance assessment.

System services & legacy systems connections.

Web based configuration.

Continuous support,
long-term referencing to the records, e.g., For
statistics,

The entire architecture is implemented based on the
concern of usability, performance, portability and easy
installation to any machine.
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Typical Features for Public
 List, browse, update, add, remove records, etc.
 Automatic linking of web page references from various places to
the course home page.
 Students can online-register, access and modify.
 Students can administer their virtual directories and personal
accounts.
 Students can take online quizzes, surveys, etc.
 Access to enhanced class web links collected.
 Students can access performance records, post office, upload
homework files,
 Automatic evaluation of results.
 Performance
tuning.
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Database Schemes
performances
Students
answers
courses
grades
questions
assignments
Surveys
exam_grades
quizzes
layouts
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Questionnaire
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Middle-tier Services








Learner Object Service(s)
Course Object Service(s)
Assignment Object Service(0s)
Quiz Object Service(s)
Survey Object Service(s)
Performance Object Service(s)
Supervisor Object Service(s)
AssessmentNugget Object Service(s)
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Learner Objects
(Logical Information Categories)






Learner personal information
Learner relations information
Learner Security information
Learner preference information
Learner performance information
Learner portfolio information
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Learner Objects
(information access controls)
 Private information  personal information, …
 Restricted access  performance information, learner
relation information, …
 Levels of public access  preference information, relations,
security
 Availability for applications  preference, relations,
performance,
 Availability for administration  personal, performance, …
 Availability for humans  learner portfolio, …
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Course Objects
(related study: SCORM)
source ~
+ externalMetadata
model ~
location ~
source ~
? curricularTaxonomy ~
model ~
location ~
? globalProperties
source ~
* extensions
course
model ~
location ~
+ property
block ~
name ~
value ~
? objectives
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VCM
Course
Objects
default = one element required;
“?” = zero or one (optional);
“+” = one or more required;
“*” = zero or more required
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Assignment
Objects
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Assignments
Online Grading & Statistics
 List, browse, add, remove, modify, publish
 On-line grading
 Access to grades is secure and private.
 Privileged levels of accessing performance records
 Various grading options and interfaces.
 Automatic evaluation reports
 Feedback information to individual students.
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Assignment Submission:
NPAC Virtual File Manager
used for uploading homework files into virtual
directories in server side, and directory-file
manipulations.[VPL]
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Quiz Objects (IMS model)
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Quiz Objects (VCM Model)
QUIZ+Assessment
QUIZ
CATEGORY+Assessment
CATEGORY
SET
Question
…
Question
SET+Assessment
Question+Assessment
…
Question+Assessment
…
…
CATEGORY
CATEGORY+Assessment
SET+Assessment
SET
Question
…
Question
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Question+Assessment
…
Question+Assessment
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(a)
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(b)
A Taxonomy of Question Types by IMS
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XSLT
Rendering
Quiz Object
Repository
(XML codings)
XSLT
Candidate
Response-Type Specific
Assessment
Generic
Assessment
Engine
Transferable, editable,
remotely accessible
XSL codings
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QUIZ SERVICE
LMS specific, final codings
in Java, C, C++, etc.
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AssessmentNugget Objects
User
Data
Filtering
Identified
Evaluation Requests
(HTML Reports
Users, Groups, Paths)
OLAPVisualization
Transaction-Session
Clarification
Web
Server
Clean Web
Logs
Logs
Transactions
(Sessions)
DATA
Collection
Traversal Paths
Transaction Association Rules
Long Term Patterns
Sequential Visit Paths
Clusters&Classification Rules
SQL
based
Querying
ASSESSMENT
OBJECT
SERVICE
VCM
Learner
Records
Data Combination
Logs
Learner
Registration
Data Filtering
and
Preparation
Performance
Records
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Students’
Responses
Data Mining
Algorithms
Virtual
Data
WareHouse
DB
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Quiz records
Transformed
data for
mining
Data Mining
Specific
Transformation
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Survey
Objects
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Performance Objects
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Supervisor Objects
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System Administration Objects
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Front-tier Customizable
Open Interfaces
 We experimented with two kind of template
structures;

Pure HTML page with inserted variable tags inside;
• simple
• very easy to edit

XSL templates to render XML objects;
• more capable,
• sophisticated for editing but now lots of commercial tools are
available.
 Both templates are editable by the final system
users
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<html>
……………
<body bgcolor=white>
<b><input type=button value="LIST" onClick="list()"></b>
<a href="$help/user.html" target=help><img
src="$images/mans.gif" border=0 align=ABSCENTER></a>
……………
<script language="JavaScript">
//<record>
document.write("<tr ---------- ><td>");
if ("$url"=="")
document.write("<img src=$images/homeempty.jpg
border=0 align=center>");
else document.write("<a href=$url target=hp><img
src=$images/homefull.jpg border=0 align=center></a>");
document.write('</td><td><a
href="frame.html?unum=$unum&comm=FRAME&framecomm=SHOW&fil
e=browse.html&gslogin=$gslogin" ><b> $la
stname, $firstname $midname </b></a></td></tr
>');
//</record>
</script>
……………
<font size=-1><i>NPAC</i></font>
</body>
</html>
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XSL
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Security Issues of an Open
Access Environment
 Communication Channel Security
 Front-end Security




User Authentication
User Access Lists
User privilege Levels (8 categories)
Presentation Security
• Uniuque and random session key, timeout-windows,
no-caching,
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Lessons on Interoperability Issues
of Distributed Components
 Integration of services (collection of
services=different systems) is necessity for

Next-generation, large-scale distance courses,
or in any other field.
 We need one big container (= framework) to
hold others such as CORBA, COM, EJB
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Software Components
 The next software model after object-oriented
paradigm, however,



Components (objects) are only usabe in their own
framework
Plug-and-play properties are not satisfied (analogies are
not true, e.g. similar to hardware comp., lego, etc.)
Non-professionals want to participate in development.
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Framework of frameworks
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Distributed Web Object Service Model
 May play equivalent role of component model,
 Properties need to be provided are:







Discoverability,
Accessibility
Interoperability
Reusability
Durability
Manageability,
And More…
 Note
that object definition
is not the one in OOP.64
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Possibility of such framework
 Technologically possible,
 There are samples; WWVM, WebFlow,
Gateway, and HTML.
 HTML is non-computational model
providing all the properties.
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Interactions of systems
 Currently we have



Machine-to-machine interaction (TCP/IP, HTTP, IIOP,
COM)
Machine-readable (XML)
Human interpretable
 We need

Machine-understandable content
 Note that XML is common language, systems are
thinking in other languages like me.
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Solutions;
 Agreeing on common standards of object
formats (syntax and semantics)


Agreeing on semantics of general properties of
objects,
Agreeing on semantics of specific field objects,
e.g. Learning System Objects
 We will get interoperability and reusability.
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RDF Model (simple example)
http://www.uefa.com/ucl/
resource
owner
author
property
name
Alice
email
value
John Smith
Properties of educational
objects, i.e., metadata, helps
to locate, access, use and
manage Web objects.
Metadata includes various
aspects of current document
like copyrights, price,
pedagogical info,
classification, rendering
info, history, relation and
links to others.
RDF (netrual,
John@email.com
resource+property+statement,
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A Description Framework of
Web-Objects (Learning Objects)
METADATA
CATOLOGING
CLIENTS
Portfolio Info Object
LMS Metadata
Recruiter Metadata
Assignment Report
….
Game Metadata
Recruiter
Programming:
Game Applet
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Assessor
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Child
NameSpace:
LMS
NameSpace: LMS
NameSpace:Science
NameSpace:
NameSpace:Government
Science
Adapter
NameSpace:
Entertainment
Adapter
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Adapter
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Global Object Service Locators
LMS 1
Course Content
Info. Services
6
5
7
1
2
8
Client
3
(LMS Application)
4
LMS
Learning Management System
Personal Info.
Services
Discoverability,
First Object Service Request
Second Object Service Request
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Durability,
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(Manageability)
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LMS 2
Web-Object Characteristics
Web
Object
Service
Web Object
<xml>
<Control>
Control
Process
………
</control>
<information>
………
CLIENT
(Web Object
Manageability; Service)
</information>
</xml>
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Programming
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capabilities
Internal
Services72
Contributions
 Scientific and architectural view of asynchronous
support in distance education.
 The multi-tier architecture model for a distributed,
open, asynchronous information access and
management environment.
 Artifact: architecture’s prototype: Virtual Classroom
Manager (VCM.).
 Lessons learnt and further/future research.
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Contributions 2
 Our generic architecture is applicable to other fields
 Our information management environment is
applicable to any human-record keeping application
development.
 Designed a new web-object service architecture as a
support for our new computing paradigm
 Proposed a new computing paradigm through object
web services. (discoverability, accessibility,
interoperability, reusability,durability,manageability, …)
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Contributions 3
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Designed inter-technology cooperation methods,
Proposed inter-disciplinary interaction methods,
We introduced new object types to LMS
We gave a complete LMS picture for learning
technology developers
 We illustrated how to use a large set of technologies
for a single system.
 We illustrated how to use a set of systems for a single
purpose
 We used objects as containers of others
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Contributions 4
 Lessons:
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Individual technologies, their computing frameworks and
platforms are no longer important
Integration of systems will make them much powerful
One system or technology is not enough to fulfill large scale
applications
Both professionals and non-professionals involved in the
environments presented by a rich set of commodity
technologies.
Technologies ( more realistically services) should be
manageable by both professionals and non-professionals.
(should be easy)
Analogies are not valid between software and other sys.
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Contributions 5
 Lessons:
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Practical social issues should be considered in
application development, I.e, LMS develop.
Some standards are too detailed, may not be long
lasting
Back-end tools, or legacy systems, are not important
• They can be utilized with full functionality
• Yet we can offer new computing models on top of them
• However, modern backend tools may be more functional,
e.g., XML Databases
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Thank you
I thank you very much
 My advisor Dr. Geoffrey Fox
 Dr. Nancy McCracken
for their great help to obtain my PhD.
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Resource Description Framework
 RDF is an abstract data model
 Cataloging(&describing collections)
• intelligent agents
 resource discovery; search service component
 describing collections of pages that represent a single
logical "document“
 RDF consists of three different types of objects
 Resource: anything with URI
 Property: a relation or an attribute used in describing
resources
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 Statement:resource+property+value