Adaptivity through the use of mobile agents in web-based student modelling.THE CONTEXT OF WEB-BASED SYSTEMS
The proliferation proliferation /pro·lif·er·a·tion/ (pro-lif?er-a´shun) the reproduction or multiplication of similar forms, especially of cells.prolif´erativeprolif´erous
n. of computers, the advent of Internet and the steady gain in the popularity of distance education greatly influence our educational environment. Educational information on the Web has increased exponentially ex·po·nen·tial
1. Of or relating to an exponent.
a. Containing, involving, or expressed as an exponent.
b. , and web-based learning is currently an important research-and-development area. Web-based learning environments are becoming mainstream applications for the educational community. However, they have a number of common deficiencies, such as limited or non-existent adaptivity for individual students, low-bandwidth connection, resulting in slow access to the course. A number of attempts have been made to circumvent cir·cum·vent
tr.v. cir·cum·vent·ed, cir·cum·vent·ing, cir·cum·vents
1. To surround (an enemy, for example); enclose or entrap.
2. To go around; bypass: circumvented the city. these problems, but a solution to one problem often impedes solutions to the remaining problems. Emerging intelligent mobile agents have huge potential to address these deficiencies.
INTELLIGENT AGENTS AND MOBILE AGENTS
An intelligent agent is a computational Having to do with calculations. Something that is "highly computational" requires a large number of calculations. entity that acts on behalf of other entities in an autonomous fashion, performs its actions with some level of proactivity and / or reactiveness and exhibits some level of the key attributes of learning, cooperation and mobility The concept of agents occurred in mid 1970s (Hewitt, 1977). However, only recently--with the strong trends in the Internet technology and distributed systems--agent technology has become one of the hot topics in information systems research and development, with particular focus on mobile agents. Their emergence occurring in the mid 1990s, mobile agents have the ability to move from one computer to another.
Mobile agent technology has been focus of research for many large research groups, for example, Telescript (White, 1996); AgentTCL (Gray, 1997); Aglet system (Chang & Lange, 1996); Bee-gent and Plangent plan·gent
1. Loud and resounding: plangent bells.
2. Expressing or suggesting sadness; plaintive: "From a doorway came the plangent sounds of a guitar" (Toshiba, 2001); and Hive (Minar, 2000). There are various benefits that mobile agents provide over static agents, such as: a) their potential to address problems of latency (1) The time between initiating a request in the computer and receiving the answer. Data latency may refer to the time between a query and the results arriving at the screen or the time between initiating a transaction that modifies one or more databases and its completion. and bandwidth in client-server applications, and the vulnerability of network disconnection--to fit into the coming dynamic and mobile age of computing computing - computer . They are bringing together telecommunications Communicating information, including data, text, pictures, voice and video over long distance. See communications. , software and distributed system See distributed computing.
distributed system - A collection of (probably heterogeneous) automata whose distribution is transparent to the user so that the system appears as one local machine. technologies to create new ways of building computing systems. The mobile agents appear to be an excellent option to address the problems of web-based learning environments.
BENEFITS OF MOBILE AGENTS
Although it is possible to propose an alternative, based on existing technology, to almost every mobile agent-based function (Chess, Harrison, & Kershenbaum, 1995), mobile agents have significant advantages over conventional approaches at the design, implementation and execution stages in most cases. The motivation for using mobile agents stems from a number of anticipated benefits:
* Efficiency and reduction in network traffic. Mobile agents consume fewer network resources since they move the computation Computation is a general term for any type of information processing that can be represented mathematically. This includes phenomena ranging from simple calculations to human thinking. to the data rather than vice versa VICE VERSA. On the contrary; on opposite sides. . Also, mobile agents can package a conversation and ship it to a destination host, where interactions can take place locally, hence, reducing the network traffic (Figure 1).
* Asynchronous Refers to events that are not synchronized, or coordinated, in time. The following are considered asynchronous operations. The interval between transmitting A and B is not the same as between B and C. The ability to initiate a transmission at either end. autonomous interaction. Tasks can be encoded into mobile agents and then dispatched Dispatched was a Swedish melodic death metal band formed in 1992 by Daniel Lundberg. Their sound is very similar to the older Gothenburg style of early In Flames. Biography
Dispatched was formed just before New Year's Eve of 1991 by Daniel Lundberg and Krister Andersson. . The mobile agent can operate asynchronously and independent of the sender program.
* Interaction with real-time entities. Real-time entities require immediate responses to changes in their environment. Controlling these entities from across a potentially large network will incur significant latencies. Mobile agents offer an alternative to save network latency See latency. .
* Local processing of data. Dealing with vast volumes of data when it is stored at remote locations, the processing of data is inefficient over the network. Mobile agents allow processing to be performed locally, instead of transmitting data over a network.
* Support for heterogeneous environments Using hardware and system software from different vendors. Organizations often use computers, operating systems and databases from a variety of vendors. Contrast with homogeneous environment. . Both the computers and networks on which a mobile agent system is built are heterogeneous in character. As mobile agent systems are generally computer and network independent, they support transparent operation.
* Convenient development paradigm. The design and construction of distributed systems Distributed systems (computers)
A distributed system consists of a collection of autonomous computers linked by a computer network and equipped with distributed system software. can be made easier by the use of mobile agents. Mobile agents are inherently distributed in nature and hence are natural candidates for such systems.
NEED OF MOBILE AGENTS IN WEB-BASED LEARNING
Institutions with long-standing involvement in distance education, such as the Open University in the United Kingdom, are incorporating web-based elements in their instruction. Although web-based course materials have obvious advantages over conventional textbooks and lecture notes, they also pose a number of problems:
* slow access to course materials, because the Internet connection bandwidth limitations, in particular for home users or remote area students;
* inadequate adaptation to individual students, because the interactions between client and server normally take place using hypertext transfer protocol See HTTP.
(protocol) Hypertext Transfer Protocol - (HTTP) The client-server TCP/IP protocol used on the World-Wide Web for the exchange of HTML documents. It conventionally uses port 80.
Latest version: HTTP 1.1, defined in RFC 2068, as of May 1997. (HTTP HTTP
in full HyperText Transfer Protocol
Standard application-level protocol used for exchanging files on the World Wide Web. HTTP runs on top of the TCP/IP protocol. ). HTTP is a stateless Refers to software that does not keep track of configuration settings, transaction information or any other data for the next session. When a program "does not maintain state" (is stateless) or when the infrastructure of a system prevents a program from maintaining state, it cannot take protocol, which makes it difficult to track the students progress and, hence, analyse an·a·lyse
v. Chiefly British
Variant of analyze.
analyse or US -lyze
[-lysing, -lysed] or -lyzing, the mental processes of the student (Kinshuk & Patel, 1997); and
* hard-to-achieve, continuous, real-time interaction between student and system, because of the connection unreliability and bandwidth limitations, or the student may not be able to maintain continuous online connection.
A number of attempts have been made to circumvent some of these problems. However, as stated before, the solution to one problem often impedes solutions to the remaining problems. For example, InterBook (Brusilovsky, Schwar, & Weber, 1996) supports adaptivity and authoring, but all adaptation and page generation takes place at the central server, risking access delays. QuestWriter (Bogley, Dorbolo, Robson, & Sechrest, 1996) supports authoring and has built-in client-side and servers side interactivity. However, it does not adapt presentations to individual students. ADE (Shaw, Ganeshan, Johnson, & Millar, 1999) uses an animated pedagogical ped·a·gog·ic also ped·a·gog·i·cal
1. Of, relating to, or characteristic of pedagogy.
2. Characterized by pedantic formality: a haughty, pedagogic manner. agent, Adele, who guides and assesses students. The Adele agent basically belongs to an intelligent interface agent, which still concentrates on providing help to students. In particular, a number of efforts have been made to implement the concept of adaptation in learning systems (Crampes 1999; Oppermann & Specht 1999). However, there have been no significant attempts to s olve the above-mentioned problems in adaptive, web-based learning environments.
The emerging mobile agent technology can not only address these problems, but also facilitate better interaction opportunities among students and teachers, and adapt to the needs of individual students.
MOBILE AGENTS AND WEB-BASED LEARNING
After examining the benefits of mobile agents--and considering the limitations of web-based learning environments--it becomes clear how mobile agent technology is capable of addressing those limitations. We will now discuss how mobile agents can improve web-based learning environments.
* In a web-base learning environment, mobile agents can be used to pre-fetch the domain content that, based on the student model, the student would most likely request in the near future (Figure 2). Mobile agents can then report the student's performance to the central server. This pre-fetch process is based on real-time analysis of the student's behaviour and calculation of the probability of a request. Each student's behaviour, as each one works through the web-based learning system, can be monitored and recorded by an intelligent interface agent, which runs on the student computer. Depending on the state of the network, an immediate request or a reservation can be made with the help of a mobile agent. In this way, end-to-end quality of service can be improved for the delivery of distributed multimedia material, such as that represented by distance education. This mobile agent technology avoids unnecessary networking delays, copes with the bandwidth limitation and adapts the representations to students base d on student performance.
* With the continuous increase in the number of mobile users, the access to web-based learning environments is increasing through portable-computing devices such as laptops, palmtops and electronic books. These devices have unreliable, low-bandwidth, high-latency telephone or wireless network connections. A mobile agent can be an essential tool for increasing the efficiency of such access.
* Mobile agents offer application developers a new programming paradigm A programming paradigm is a fundamental style of programming regarding how solutions to problems are to be formulated in a programming language. (Compare with a methodology, which is a style of solving specific software engineering problems). with higher-level abstraction In object technology, determining the essential characteristics of an object. Abstraction is one of the basic principles of object-oriented design, which allows for creating user-defined data types, known as objects. See object-oriented programming and encapsulation.
1. and a unified process The Unified Software Development Process or Unified Process is a popular iterative and incremental software development process framework. The best-known and extensively documented refinement of the Unified Process is the Rational Unified Process or RUP. and object. In terms of scalability of the system and easy authoring, these features of mobile agents offer a flexible and effective philosophy on learning environment development, design and scalability.
* In the future, web-based learning environments can share resources through different systems (Figure 3). Both the computers and networks on which web-based systems are built are also heterogeneous in character. As mobile agent systems are generally computer and network independent, they provide excellent support for distributed systems and resources sharing.
* From the perspective of emerging mobile agent technology, web-based learning environments are the ideal test beds for this technology. Until now, electronic commerce has been treated as the only important target for mobile agent technology. Money is involved, therefore, security is a key factor for agent technology. There are three types of security: agent-agent security, host-agent security and agent-host security. Existing techniques can be successfully applied to protect agents from malicious Involving malice; characterized by wicked or mischievous motives or intentions.
An act done maliciously is one that is wrongful and performed willfully or intentionally, and without legal justification.
DESERTION, MALICIOUS. agents and hosts from malicious agents. Currently, however, it is difficult to protect the agents from malicious hosts. This is due to the possibility of the host changing the programming code of the agent for vested interests vested interest
1. Law A right or title, as to present or future possession of an estate, that can be conveyed to another.
2. A fixed right granted to an employee under a pension plan.
3. . This factor is one of the main obstacles affecting mobile agent applications in the commercial sector. However, in the education sector, agent-host security is not as vital. This makes the web-based learning environments the most suitable test bed for mobile agents technology.
A prototype, web-based intelligent tutoring system An intelligent tutoring system (ITS), broadly defined, is any computer system that provides direct customized instruction or feedback to students, i.e. without the intervention of human beings. ITS systems may employ a host of different technologies. (WBITS WBITS Web-Based Integrated Training System (US Air Force Reserve) ) was built to exploit student adaptivity in a web-based environment by using traditional client-server technology (Han, 2001). This system benefited from collaborative learning Collaborative learning is an umbrella term for a variety of approaches in education that involve joint intellectual effort by students or students and teachers. Collaborative learning refers to methodologies and environments in which learners engage in a common task in which each on the Web by having two separate student models: individual student models for each student, and group student models for generalizing a group of students' attributes. However, the potential of the individual student and group student models' mechanisms in the WBITS was not exploited fully, and it also had the common deficiencies of web-based learning systems. Therefore, the system was redesigned using mobile agent technology In the following section, we provide a brief description of the original system and then discuss the mobile agents-based architecture and implementation.
ARCHITECTURE OF WBITS
The WBITS system was implemented with a three-tier, client-server architecture client-server architecture
Architecture of a computer network in which many clients (remote processors) request and receive service from a centralized server (host computer). (Figure 4) (Han, 2001).
* Client tier: a web browser The program that serves as your front end to the Web on the Internet. In order to view a site, you type its address (URL) into the browser's Location field; for example, www.computerlanguage.com, and the home page of that site is downloaded to you. runs on the student computer. This tier is mainly responsible for handling the adaptive presentation of course materials and dynamically tracking student working process.
* Middle tier (1) Generally refers to the processing that takes place in an application server that sits between the user's machine and the database server. The middle tier server performs the business logic. See application server and client/server. : it resides in the server side, where it handles the student model initialisation Noun 1. initialisation - (computer science) the format of sectors on the surface of a hard disk drive so that the operating system can access them and setting a starting position
initialization, low-level formatting and update logic. It is responsible for receiving client requests, processing the data contained in the requests, applying student model initialisation and update logic to the data, and generating a client response based on the updated student model.
* Database tier: the backend database resides on the server side and stores the data including the student model, which is required by the middle tier.
ADAPTIVITY AND COMMUNICATION IN WBITS
To implement the adaptivity within the system, the WBITS used two types of student models: the individual student model and the group student model.
* Individual student model: it is represented by an overlay (1) A preprinted, precut form placed over a screen, key or tablet for identification purposes. See keyboard template.
(2) A program segment called into memory when required. model, in which the current state of a student's knowledge level is described as a subset A group of commands or functions that do not include all the capabilities of the original specification. Software or hardware components designed for the subset will also work with the original. of the domain model. The domain-independent data within the individual model is initialised by explicit questioning, while the domain specific data is initialised by using the default values. Students can modify their domain-independent data, but the domain-specific data is updated by tracking students' progress.
* Group student model: it is constructed by averaging corresponding values in the individual student models within a group. The statistical data for the group student model is produced dynamically from individual model databases.
Both the individual student and group student models reside on the server.
The communication between client and server was primarily implemented with HTTP socket techniques. When clients send a request to the server, an HTTP socket connection is opened and the request is sent. Then the client waits for the response from the server.
THE ADAPTATION MECHANISM
Although a number of attempts have been made to implement the concept of adaptation in learning systems, no significant attempts have been made to provide adaptation in web-based learning. This circumstance Circumstance or circumstances can refer to:
Kinshuk, Oppermann, Patel arid ar·id
1. Lacking moisture, especially having insufficient rainfall to support trees or woody plants: an arid climate.
2. Kashihara (1999) observed that improving the dynamic adaptation in systems requires consideration of following criteria:
(a) adaptation with respect to the current domain competence level of the learner;
(b) suitability with respect to domain content; and
(c) adaptation with respect to the context in which the information is being presented.
Moving the adaptation mechanisms from standalone stand·a·lone
Self-contained and usually independently operating: a standalone computer terminal. intelligent tutoring systems to the web-based learning systems, a suitable mechanism was developed to: a) capture interactions over the Internet, and b) provide a continuous interaction pattern for a given student, even m offline mode or with an unreliable connection. The high-level architecture of adaptation in the system is presented in Figure 5.
As seen here, the system uses two separate student models:
1. Individual student model serves an individual student and contains detailed information about students' domain competence levels, preferences, interaction information and other relevant details. A partial individual student model resides on the central server, and the remainder of the individual student model is on the user's machine (local server).
2. Group student model, which generalises various attributes over a number of students and attempts to classify clas·si·fy
tr.v. clas·si·fied, clas·si·fy·ing, clas·si·fies
1. To arrange or organize according to class or category.
2. To designate (a document, for example) as confidential, secret, or top secret. students in various categories (according to according to
1. As stated or indicated by; on the authority of: according to historians.
2. In keeping with: according to instructions.
3. various stereotypes attributes), resides on the central server.
This two-step modelling mechanism has largely improved the capturing process of interactions of a given student in the web-based learning environment. This mechanism has also enabled the system to provide adaptation at various granularity The degree of modularity of a system. More granularity implies more flexibility in customizing a system, because there are more, smaller increments (granules) from which to choose. levels by having the following advantages:
* It allows the system to be much more flexible, particularly in the web-based environment, where connectivity between host and client is not always guaranteed and the quality of the connection often suffers from traffic congestion The condition of a network when there is not enough bandwidth to support the current traffic load.
congestion - When the offered load of a data communication path exceeds the capacity. .
* It facilitates offline adaptation with intermittent intermittent /in·ter·mit·tent/ (-mit´ent) marked by alternating periods of activity and inactivity.
1. Stopping and starting at intervals.
2. updates of the server-side student model when possible.
* Students can access their models and courses online from other computers, with intermittent updates of the client-side student model when possible.
* The central server-side student model allows adaptivity based on new information available from the domain experts and better adaptation procedures resulting from group student model.
The inference engines The processing program in an expert system. It derives a conclusion from the facts and rules contained in the knowledge base using various artificial intelligence techniques.
inference engine - A program that infers new facts from known facts using inference rules. are employed at both the client and server sides to enable two-way update of information. The engine at the server side is also used to extract common attributes from individual student models and process advisements and initialisations for individual student.
Although such a two-fold student modelling proved useful, the system was still suffering from the common deficiencies of web-based learning environments discussed earlier. Therefore, we redesigned the system using the mobile agents technique.
ARCHITECTURE OF THE SYSTEM USING MOBILE AGENTS TECHNOLOGY
The mobile agents technology has been used in the system to implement the adaptation mechanism. Figure 6 describes the implementation of mobile agents technology in the system.
As seen here, the mobile agent basically interacts with the client-side inference engine to pick up data, which relies on the individual student model on the client side. Then, the mobile agent moves to the server side. Here, the agent performs all the processes needed, such as updating the partial individual student model based on the summary of the client-side student model brought by a mobile agent, interacting with the group student model to update it, if required. After the mobile agent finishes all updated tasks on the server side, it gathers all the information it needs to update the client-side model and return to the client side. Then, it updates the client-side individual student model. The mobile agent approach even works when there is intermittent connectivity between the client and server because a mobile agent can be dispatched and work autonomously.
SYSTEM DESIGN USING BEE-GENT FRAMEWORK
The Bee-gent mobile agent framework (http:// www2.toshiba.co.jp/beegent/index.htm) is used to implement the mobile agent in the system. The wrapper A data structure or software that contains ("wraps around") other data or software, so that the contained elements can exist in the newer system. The term is often used with component software, where a wrapper is placed around a legacy routine to make it behave like an object. agents are used to wrap the client- and server-side systems, and the mediation mediation, in law, type of intervention in which the disputing parties accept the offer of a third party to recommend a solution for their controversy. Mediation has long been a part of international law, frequently involving the use of an international commission, agents are used to perform the communication and exchange information with the wrapper agents (Figure 7). There are three main processes within the system.
(A) At the server side, the inference engine interacts with the group student model and partial individual student model through the database interface. The inference engine also checks whether something has been updated within the database and if the update has been sent to the client, periodically. If something needs to be sent to clients, the inference engine notifies the wrapper agent with the information that needs to be sent. The wrapper agent then creates a mediation agent carrying the information and related program and launches the mediation agent. If the mediation agent cannot find the target clients, it comes back to notify the failure of the update process and keeps monitoring the path to the target client. If the mediation agent reaches the target client, it communicates and exchanges information with the client's wrapper agent. In turn, the client's wrapper agent communicates with its inference (logic) inference - The logical process by which new facts are derived from known facts by the application of inference rules.
See also symbolic inference, type inference. agent to transmit the data. The inference agent processes the data to update the client side student m odel.
(B) To update the group student model at the server side, the server side engine extracts the information from all partial individual student models available at the server side.
(C) From the client side, the procedure is similar as those described above, except that the inference engine only interacts with the partial individual student model.
The functionality of mediation agents--whether they are created by the server or client--is the same.
* They communicate with destination servers and exchange information with servers.
* They notify their creator when the connection is not available and/or the update processes fail.
* They move to different servers.
* Once launched, they are not affected by the status of their sender, whether the sender is online or offline.
Both server-side and client-side wrapper agents are simply the interfaces between mediation agents and inference engines. When wrapper agents receive visiting mediation agents, they act as translators This is primarily a list of notable Western translators. Please feel free to add translators from other languages, cultures and areas of specialization. Large sublists have been split off to separate articles. that pass the information back and forth between the mediation agents and the inference engines. When wrapper agents receive requests from inference agents to send mediation agents, they create mediation agents and launch them.
The inference engines are the core components of the system. They initialise (programming) initialise - To give a variable its first value. This may be done automatically by some languages or it may require explicit code by the programmer. Some languages allow initialisation to be combined with variable definition, e.g. most processes and control the process flow.
The main functions of the client-side inference engine are as follows.
* It periodically checks the update information in the individual student model and determines whether the update of the server-side individual student model should take place. If yes, it passes the data to the wrapper agent for creation of mediation agents.
* If updates fail because of the connection problems or unavailability of the server for any reasons, the inference engine informs the student model database.
* It receives information from its corresponding wrapper agents and updates the student model.
The server-side inference engine includes the functionality of the client-side inference engine, plus the following features:
* It periodically extracts and generalises the attributes from all partial individual student models--available at the server side--within a group to dynamically update the group student model.
* It initialises a new student model based on the group student model by sending a mediation agent to client.
* It classifies students to various groups within the group student model.
Individual and group student model databases
The client-side partial individual student model stores extensive information about students such as their domain competencies, interaction with the system, personality attributes as recorded by the system and so forth. The server-side, partial individual student model contains only the summarised information that has been brought and updated by the mediating agents from time to time.
The group student model contains the groups created by assessing common attributes of the students and classifying them accordingly. It can dynamically add more groups and attribute within the groups depending on the results received from the inference engine.
Services between Client and Server
* Figure 8 represents the services that take place between the client and the server when a client intends to update the partial individual student model on the server. A timer timer,
n radiographic timing device that functions as an automatic exposure timer and a switch to control the current to the high-tension transformer and filament transformer. The face of the timer is calibrated in seconds and fractions of seconds. has been set up for this purpose to fire the notification event for the inference engine to check the individual student model on the client. The basic algorithm is described in Table 1.
* When the server-side partial individual student model needs to update the client-side corresponding student model, the mechanism and procedure are identical to the above procedure of updating the server-side model by the client side.
* Initialisation of the new student's profile. In the WBITS system, the individual student model database consists of domain-independent data and domain-specific data. The domain-independent data is initialised by explicit questioning--or default values when the student chooses not to specify preferences. Using the generalised Adj. 1. generalised - not biologically differentiated or adapted to a specific function or environment; "the hedgehog is a primitive and generalized mammal"
biological science, biology - the science that studies living organisms domain-independent data of an individual student model within a group, the new student's domain independent data is initialised with the individual's student model (Figure 9). The basic algorithm for initialising the new student's model is presented in Table 2.
Interaction protocols in the system
Interaction protocols for individual student model update
Interaction protocols define the behaviours of the different parties within the system. This means system functionality is based on the interaction protocols and achieved by message exchanges between parties. Thus, the communication and how to perform the tasks within the system is programmed based on the interaction protocols.
The interaction protocols are presented by state transition diagrams state transition diagram - A diagram consisting of circles to represent states and directed line segments to represent transitions between the states. One or more actions (outputs) may be associated with each transition. The diagram represents a finite state machine. . These diagrams for each wrapper agent and mediation agent--when the client intends to update the individual student model on the server--are shown in Figure 10.
For the server-side partial individual student model to update the client-side corresponding student model, the state transition diagram is similar to the one from the client side to the server side, except from the other direction, from server to client.
Interaction protocols for individual student model initialisation from group student model
When a new student chooses not to define personal preferences for domain-independent data, the corresponding domain-independent data within group student model, generalised from students' common preferences, initialises the student's preferences. Figure 11 is the state transition diagram of each wrapper agent and mediation agent.
In this research, we exploited the benefits of two major technological solutions: two-fold student models, and mobile agents. Although formal evaluation of the system has not taken place, informal assessment has shown evidence of the enhancement in the quality of adaptation. We have also been able to address common deficiencies found in web-based learning environments. The main contributions of this research are described in the following section.
Improving Adaptivity in Web-based Learning Environments
Improvement in adaptivity for the student has been the main focus of this research. It is achieved in two ways:
A) Dividing the student model into three parts: local and central individual student models and central group student model (Figure 5).
This two-step modelling mechanism largely improves the capturing of interactions of a given student in the web-based learning environment, even in offline mode, and enables the system to provide adaptation at different granularity levels.
B) Applying mobile agents technology as the communication channel between client and server, instead of traditional client-server approaches.
The Bee-gent mobile agent framework of Toshiba is used in the prototype. Since mobile agents are inherently distributed in nature and have certain qualities--such as pre-fetching data, local processing of data and autonomous procedures--these agents possess the ideal technology to implement the mechanisms of the local and central individual student model and central group student model built in this research.
Hence, in this prototype, the mechanism of student models implemented by mobile agent technology addresses the problem of inadequate adaptation to individual students commonly found in the web-based learning environments.
Providing a flexible framework for maintenance and scalability
Mobile agents, in particular the Bee-gent framework, are implemented with higher-level abstraction and unified object. Therefore, they enable the prototype to provide a flexible and effective environment for future scaling and maintenance of the systems. For example, to bind the existing systems into this prototype will not affect the whole architecture because that would require only the creation of another wrapper agent to wrap the existing system and mediation agents to exchange the data.
Support for heterogeneous environments
Ideally, the development of web-based learning environments should share the existing resources available on different systems and different platforms. The prototype built with mobile agents fulfils that requirement because they have the capability to execute the processes in different environments. In particular, the Beegent mobile agents framework is built on Java, which is, for the most part, a platform-independent language.
Support for mobile students
Mobile users experience problems--such as unreliable, low-bandwidth, high-latency telephone or wireless network connections--while accessing web resources through portable computing devices. Essentially, the two-fold student model architecture and mobile agents technology facilitate the web-based learning systems to be used efficiently through these devices.
Table 1 Basic algorithm If the inference engine receives an event from the timer Then check the new data flag within the student model If the new data flag is No Then do nothing Else get the new data and set the new data flag to No send request to agent wrapper asking to create mobile agent agent wrapper creates and launch a mediation agent with the new data If client is offline Then notice inference to set the new data flag back to Yes Elseif server not found Then notice inference to set the new data flag back to Yes Else update is done If more than one server Then mediation agent moves to next server If server wants to send data to client by the agent Then the mediation agent get the data and back home End If Table 2 Basic algorithm for initialising the new student's model If the new student does not define preferences in domain independent data Then send a request by mobile agent from client to server to retrieve the domain independent data from group student model, which is generalized from the individual student model within the group If more than one server Then mediation agent moves to next server until finished End If
Bogley, WA., Dorbolo, J., Robson, RO., & Sechrest, JA. (1996). New pedagogies and tools for web-based calculus calculus, branch of mathematics that studies continuously changing quantities. The calculus is characterized by the use of infinite processes, involving passage to a limit—the notion of tending toward, or approaching, an ultimate value. . In H. Maurer (Ed.), WebNet 96: World Conference of the Web Society Proceedings (pp. 33-39). Charlottesville, VA: Association for the Advancement of Computing in Education.
Brusilovsky, P.L., Schwar, E., & Weber, G. (1996). ELM-ART: An intelligent tutoring system on World Wide Web. In C. Frasson, G. Gauthier, & A. Lesgold (Eds.), Intelligent tutoring systems: Lecture notes in computer science Lecture Notes in Computer Science (LNCS) is a computer science series published by Springer Science+Business Media. , Vol. 1086 (pp. 261-269). Berlin: Springer-Verlag.
Chang, D., & Lange, D. (1996). Mobile agents: A new paradigm New Paradigm
In the investing world, a totally new way of doing things that has a huge effect on business.
The word "paradigm" is defined as a pattern or model, and it has been used in science to refer to a theoretical framework. for distributed object Distributed objects are software modules that are designed to work together, but reside either in multiple computers connected via a network or in different processes inside the same computer. computing on the WWW Paper presented at the OOPSLA'96 Workshop: Toward the integration of WWW and distributed object technology, San Jose San Jose, city, United States
San Jose (sănəzā`, săn hōzā`), city (1990 pop. 782,248), seat of Santa Clara co., W central Calif.; founded 1777, inc. 1850. , CA. Retrieved from the World Wide Web July 10, 2002, from Massachusetts Institute of Technology Massachusetts Institute of Technology, at Cambridge; coeducational; chartered 1861, opened 1865 in Boston, moved 1916. It has long been recognized as an outstanding technological institute and its Sloan School of Management has notable programs in business, website at http://www.mit.edu/~yandros/doc/mobileagents.html.
Chess, D., Harrison, C., & Kershenbaum, A. (1995). Mobile agents: Are they a good idea? (Technical Report No. 19887 (88465)) Yorktown Heights, NY: IBM (International Business Machines Corporation, Armonk, NY, www.ibm.com) The world's largest computer company. IBM's product lines include the S/390 mainframes (zSeries), AS/400 midrange business systems (iSeries), RS/6000 workstations and servers (pSeries), Intel-based servers (xSeries) T.J. Watson Research Center. Retrieved from the World Wide Web July 10, 2002, from http://www.research.ibm.com/massive/mobag.ps,
Crampes, M. (1999). User controlled adaptivity versus system-controlled adaptivity in intelligent tutoring systems. In S.P. Lajoie & M. Vivet (Eds.), Artificial intelligence in education (pp. 173180). Amsterdam: 105 Press.
Gray, R.S. (1997). AgnetTCL: A flexible and secure mobile-agent system. Doctoral thesis, Dartmouth College Dartmouth College, at Hanover, N.H.; coeducational; chartered 1769, opened 1770, the ninth colonial college (see Wheelock, Eleazar). Originally a men's college, Dartmouth began admitting women in 1972. , Hanover, NH.
Han, B. (2001). Student modelling and adaptivity in web-based learning systems. Master's thesis, Computer Science Department, Massey University Massey University (Māori: Te Kunenga ki Purehuroa) is New Zealand's largest university with approximately 40,000 students. It has campuses in Palmerston North (sites at Turitea and Hokowhitu), Wellington (in the suburb of Mt Cook) and , Palmerston North Palmerston North, city (1996 pop. 73,095), S North Island, New Zealand. It is a transportation and farm-marketing center with diverse industries. The city's agricultural college, founded in 1926, became Massey Univ. in 1964. , New Zealand New Zealand (zē`lənd), island country (2005 est. pop. 4,035,000), 104,454 sq mi (270,534 sq km), in the S Pacific Ocean, over 1,000 mi (1,600 km) SE of Australia. The capital is Wellington; the largest city and leading port is Auckland.
Hewitt, C. (1977). Viewing control structures as patterns of passing messages. Artificial Intelligence, 8(3), 323-364.
Kinshuk, & Patel, A. (1997). A conceptual framework For the concept in aesthetics and art criticism, see .
A conceptual framework is used in research to outline possible courses of action or to present a preferred approach to a system analysis project. for Internet-based intelligent tutoring systems. In A. Behrooz (Ed.), Knowledge transfer, Volume 2 (pp. 117-124). London: Pace.
Kinshuk, Oppermann, R., Patel, A., & Kashihara, A. (1999). Multiple representation approach in multimedia based intelligent educational systems. In SR Lajoie & M. Vivet (Eds.), Artificial intelligent in education (pp. 259-266). Amsterdam: IOS (1) (Internetwork Operating System) An operating system from Cisco that is the primary control program used in its routers. IOS is widely used and robust system software that supports the common functions of all products under Cisco's CiscoFusion architecture. Press.
Minar, N. (2000). Hive: Distributed agents for networking things. IEEE (Institute of Electrical and Electronics Engineers, New York, www.ieee.org) A membership organization that includes engineers, scientists and students in electronics and allied fields. concurrency Operations that are performed simultaneously within the computer. For example, dual-core CPUs provide complete overlapping of two independent processes. See dual core, hyperthreading, multiprocessing, multitasking, multithreading, SMP and MPP.
concurrency - multitasking 8(3), 24-33.
Oppermann, R., & Specht, M. (1999). Adaptive mobile museum guide for information and learning on demand. In H.J. Bullinger & J. Ziegler (Eds.), Human computer interaction: Communication, cooperation, and application design (pp. 642-646). Mahwah, NJ: Lawrence Erlbaum Associates.
Shaw, E., Ganeshan, R., Johnson, W.L., & Millar, D. (1999). Building a case for agent-assisted learning as a catalyst for curriculum reform in medical education. Paper presented at the AIEd'99 Workshop on Animated and Personified Pedagogical Agents.
White, J.E. (1996). Telescript technology: Mobile agents. In J. Bradshaw (Ed.), Software agents (437-472). Cambridge, MA: AAAI AAAI American Association for Artificial Intelligence
AAAI Association for the Advancement of Artificial Intelligence (Menlo Park, California)
AAAI American Academy of Allergy, Asthma, and Immunology Press/MIT Press.
Toshiba (2001). Bee-gent[TM]: Bonding and encapsulation (1) In object technology, the creation of self-contained modules that contain both the data and the processing. See object-oriented programming.
(2) The transmission of one network protocol within another. enhancement [Software]. Retrieved from the World Wide Web June 19, 2002, from: http://www2.toshiba.co.jp/beegent'index.htm
KINSHUK & HONG HONG, MASSEY UNIVERSITY, PALMERSTON NORTH, NEW ZEALAND E-MAIL e-mail: see electronic mail.
in full electronic mail
Messages and other data exchanged between individuals using computers in a network. : email@example.com
ASHOK PATEL Ashok Kurjibhai Patel , (born 6 March 1957 in Bhavnagar, India) is a former Indian cricketer. DE MONTFORT UNIVERSITY De Montfort University (DMU) is a British university situated in Leicester, England. History
De Montfort University, which is named after Simon de Montfort who was Earl of Leicester in the 13th century, is one of two universities situated in the , LEICESTER, UNITED KINGDOM E-MAIL: firstname.lastname@example.org