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Slide1: 

A Distributed Open Asynchronous Information Access and Management Environment by Mehmet Sen EECS, Syracuse University Advisor: Geoffrey C. Fox November 30, 2000

Outline: 

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

What Is Our Research?: 

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.

MotivationsWhy are we doing this research?: 

Motivations Why are we doing this research? Learning technologies are improved in last half-decade as well as technologies in other fields. Commodity technologies are shaping learning technologies. (Complete web-based learning environments). Prior to 1998 1999 2000 Primitive applications of technology Widespread Technology Tries STANDARDS APPEARING Technology applications in learning

Basic Needs and Problems Encountered Leading to Our Research: : 

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 generated evaluation reports, etc.

Need for Further ResearchWhy do we need to research, is there difference?: 

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.

Major Contributions: 

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.

A Compact Taxonomy of Learning Technologies: 

A Compact Taxonomy of Learning Technologies Content preparation Content delivery: Asynchronous Synchronous Information management

Advances in Learning SystemsWhat is done as learning systems?: 

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 & Distribution Networks for Europe)

IEEE LTSA (architecture) by Learning Technology Systems Consortium (LTSC): 

IEEE LTSA (architecture) by Learning Technology Systems Consortium (LTSC) framework for general learning technology systems (to understand sys.) Neutral, promotes interoperability in 5-10 years V C M

Traditional classroom mapped to LTSA system components: 

Traditional classroom mapped to LTSA system components

VCM mapped to LTSA system components: 

VCM mapped to LTSA system components

How Do Standards Come Alive?: 

How Do Standards Come Alive? LTSC (P1484) IEEE, ANSI, ISO: Accredited Standards Liaison Liaison Liaison Education & Learning Technology Orgs: AICC, ADL, IMS, ARIADNE

Standardization Efforts in Learning Technologies I: 

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]

Standardization Efforts in Learning Technologies II: 

Standardization Efforts in Learning Technologies II Metadata: IMS Metadata for describing learning resources IEEE LOM Learning Object Metadata describes learning content cataloging information (basically proposed by IMS and ARIADNE)

Standardization Efforts in Learning Technologies III: 

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. )

Standardization Efforts in Learning Technologies V: 

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

Further Organizations: 

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.

Open Standards & Technologies: 

Open Standards & Technologies HTML, DHTML, JavaScript, JSP XML, XSL, RDF, DOM, SAX Java, Servlets, HTTP, IIOP, COM DCOM, CORBA, EJB, RMI

Open technologies & Learning Standards: 

Open technologies & Learning Standards Will(may) provide us: 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.

What Standards and Current Practices Miss ?: 

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 long-lasting (or equivalently problematic in long term)

Our Multi-Tier ArchitecturesOur very first short termed architecture: 

HTML+JavaScript Our Multi-Tier Architectures Our very first short termed architecture Database Web Server Database Bridge Database Connection script OWA, or WOW+wowstub Oracle Web Server client

Current architecture: 

Database Legacy Bridge Legacy Systems Database Bridge Current architecture client

Slide24: 

Database Bridge Database Legacy Bridge Legacy Systems Web Object Web Object Web Object Web Server System Manager Object Providers High Level Object Request Brokers Services WO WO WO WO Represents Web Object

Slide25: 

Multi-Tier Architecture(implementation view)

Issues on Web Objects: 

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

DB to WEB With XML (Object Service View): 

Web Server Servlets DB DOM Object Provider, Broker JDBC XSL Templates DB to WEB With XML (Object Service View) HTTP, IIOP, RMI, DCOM, TCP/IP Socket HTTP

Features of VCM: 

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,

Features of VCM II: 

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.

Typical Features for Public: 

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.

Database Schemes: 

Students exam_grades assignments courses Users performances layouts Questionnaire Database Schemes

Middle-tier Services: 

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)

Learner Objects (Logical Information Categories): 

Learner Objects (Logical Information Categories) Learner personal information Learner relations information Learner Security information Learner preference information Learner performance information Learner portfolio information

Learner Objects(information access controls): 

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, …

Course Objects(related study: SCORM): 

Course Objects (related study: SCORM)

VCMCourseObjects: 

default = one element required; “?” = zero or one (optional); “+” = one or more required; “*” = zero or more required VCM Course Objects

Assignment Objects: 

Assignment Objects

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. Assignments Online Grading & Statistics

Assignment Submission: NPAC Virtual File Manager: 

used for uploading homework files into virtual directories in server side, and directory-file manipulations.[VPL] Assignment Submission: NPAC Virtual File Manager

Quiz Objects (IMS model): 

Quiz Objects (IMS model)

Quiz Objects (VCM Model): 

Quiz Objects (VCM Model)

A Taxonomy of Question Types by IMS: 

A Taxonomy of Question Types by IMS

Slide47: 

Quiz Object Repository (XML codings) Candidate XSLT Rendering XSLT Response-Type Specific Assessment Generic Assessment Engine QUIZ SERVICE Transferable, editable, remotely accessible XSL codings LMS specific, final codings in Java, C, C++, etc.

AssessmentNugget Objects: 

AssessmentNugget Objects

Survey Objects: 

Survey Objects

Performance Objects: 

Performance Objects

Supervisor Objects: 

Supervisor Objects

System Administration Objects: 

System Administration Objects

Front-tier Customizable Open Interfaces: 

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

Slide58: 

<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=$unum&comm=FRAME&framecomm=SHOW&file=browse.html&gslogin=$gslogin" ><b> $la stname, $firstname $midname </b></a></td></tr >'); //</record> </script> …………… <font size=-1><i>NPAC</i></font> </body> </html>

Slide59: 

XSL

Security Issues of an Open Access Environment: 

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,

Lessons on Interoperability Issues of Distributed Components : 

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

Software Components: 

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.

Slide63: 

Framework of frameworks

Distributed Web Object Service Model: 

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.

Possibility of such framework: 

Possibility of such framework Technologically possible, There are samples; WWVM, WebFlow, Gateway, and HTML. HTML is non-computational model providing all the properties.

Interactions of systems : 

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.

Solutions;: 

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.

RDF Model (simple example): 

RDF Model (simple example) http://www.uefa.com/ucl/ John Smith owner name John@email.com email Alice author 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, resource+property+statement, property resource value

A Description Framework of Web-Objects (Learning Objects): 

A Description Framework of Web-Objects (Learning Objects)

Slide70: 

Adapter NameSpace: LMS NameSpace:Science NameSpace:Government NameSpace: LMS NameSpace: Entertainment NameSpace: Science Adapter Adapter

Slide71: 

Client (LMS Application) Personal Info. Services Course Content Info. Services 1 3 2 4 7 8 6 5 First Object Service Request Second Object Service Request LMS 1 LMS 2 Global Object Service Locators LMS Learning Management System Discoverability, Durability, (Manageability)

Web-Object Characteristics: 

Web-Object Characteristics Web Object <xml> <Control> ……… </control> <information> ……… </information> </xml> CLIENT (Web Object Service) Web Object Service Control Process Internal Services Manageability; Programming capabilities

Contributions: 

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.

Contributions 2: 

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, …)

Contributions 3: 

Contributions 3 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

Contributions 4: 

Contributions 4 Lessons: 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.

Contributions 5: 

Contributions 5 Lessons: 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

Thank you: 

Thank you I thank you very much My advisor Dr. Geoffrey Fox Dr. Nancy McCracken for their great help to obtain my PhD.

Resource Description Framework: 

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 Statement:resource+property+value