A Model For Learning Objects Reusability

Designing systems from scratch is an old fashioned concept nowadays. Availability of reusable components allows the developers to concentrate less on coding but more on reuse of these components in their application. If an application can be developed with such an approach then why not the material designed for E-learning. This paper focuses on Learning objects (LO), the core concept in E-learning reusability and suggests a model to check for reusability of an LO under consideration. Various metrics used in software engineering are used for that purpose.

Introduction: E-learning is the delivery of instructions using network and multimedia computer facilities, and has become an important part of modern education for universities and corporations by complementing traditional in-class education. One of the challenges for distance learning is the creation of high quality course materials (lecture notes, references, tests, etc). While intelligent technology is still under development to automatically aggregate sufficient course materials, an instructional technology learning objects (LOs) currently leads other candidates for the position of technology of choice in next generation of instructional design, development and delivery. It is important to share and reuse well-developed learning objects (i.e., decomposed reusable objects as a course material) to reduce the load on instructors, and to make them available across a wide variety of platforms. Thus, the concept of reusability in e-learning is an interesting issue for education professionals, system developers, and learners [2].

According to Learning technology standards committee (LTSC ) “Learning Objects are defined  as any entity, digital or non-digital, which can be used, re-used or referenced during technology supported learning. Examples of technology-supported learning include computer-based training systems, interactive learning environments, intelligent computer-aided instruction systems, distance learning systems, and collaborative learning environments. Examples of Learning Objects include multimedia content, instructional content, learning objectives, instructional software and software tools, and persons, organizations, or events referenced during technology supported learning” (LOM, 2000). Also “any digital resource that can be reused to support learning” can be called as learning object.[3]

2.    Factors contributing reusability in LO Metadata: To make reusability of learning objects possible it is necessary that they are easily accessible from the libraries so as to enable computer agents to automatically and dynamically compose personalized lessons for an individual learner.
 
The Learning Objects Metadata Working Group is working to create metadata for learning objects (such as Title, Author, Version, Format, etc.) so that people and computers will be able to find objects by searching, as opposed to browsing the entire digital library one object at a time until they find a satisfying one.

3.    Combination: Once the LOs are collected from the libraries, now they need to be arranged in a proper sequence to fulfill the required objective and that is said to be as the combination or sequential aspect of LOs.


4.    Granularity: Another aspect related to reusability of LO is the granularity, means the size of the learning object. Bigger the size, the room for reuse becomes lower. Smaller the size, the cost of creation of metadata increases. From efficiency point of view the decision regarding LO granularity can be viewed as a trade off between the possible benefits of reuse and expense of cataloging.

5.    Granularity Framework: Learning objects can exist at different levels of granularity or aggregation. At the lowest level of the granularity hierarchy are assets, which are normally single files such as an image, some text, or a video, or audio clip. The next level of granularity occurs when assets are aggregated into some meaningful structure called an information object. Structured information objects can then be aggregated into coarser grained components, and the process repeated again and again to produce increasingly coarser grained learning objects [5]. The objects at each level of aggregation can all be considered learning objects, although they may correspond to the educational terms of topics, lessons, modules, or courses. Figure 1 shows a learning object granularity hierarchy that can be used as a basis for creating increasingly granular learning objects.

6.    Coupling and cohesion in LO: Coupling and cohesion, two key software engineering principles, played an important role in the design of learning objects. In object oriented software engineering coupling refers to degree to which a particular object is connected to or knows about other objects. The principle of low coupling is directly application to the design of LOs. Coupling between learning objects is manifested by links that allow one LO to be accessed from another. It is also manifested by one learning object making forward or backward references to another LO.

If a LO is to be reused all the LOs that are linked to, or referred to, by this learning object must also be reused. This makes maintenance difficult and also makes reusability difficult since the features of the coupled learning objects must also be taken into consideration [4]. Thus, low coupling is an important principle for creating learning objects that can be reused in different contexts. The principle of cohesion in object-oriented software engineering refers to the extent to which the functionality of an object is logically related. In the context of learning objects, a highly cohesive learning object is designed to achieve one or more well-focused learning objectives that are closely related. The content of the LO is also tightly integrated so that the learning object does not do too little or too much. A learning object with low cohesion is evidenced by bloated content that is badly focused and which addresses several learning objectives at the same time. Thus while designing the learning objects it should be kept in mind that the levels of cohesion are high and coupling low. So as to integrate them into higher level coarser-grained units of instruction.

7.    A general model for LO reusability: As coupling and cohesion play an important role to determine the reusability of LO, a model can be prepared which on the parameters of metrics use to measure level of granularity, coupling, cohesion and complexity and can predict whether the LO under study is suitable for reuse under the framework or not.

8.    Algorithm:
1.    Read the LO whose reusability has to be defined.
2.    Analyze the read LO to find for complexity, no. of contents (size), inter and intra module relationship, depth of reuse tree, clarity, understandability and granularity.
3.    Call for a justification module, which on the basis of metrics determine the reusability probability of concerned LO.
4.    If the justification module gives a green signal to the reusability level of the concerned LO, this can be declared as a reusable LO. Otherwise, necessary changes depending upon the recommendations of justification module can be done and the LO is reanalyzed for further consideration.

9.    Working of Justification Module: In this module the recommendation of various metrics from the field of software engineering is given to check for the reusability of a learning object. Particular metrics and their purpose used above in the model are Weighted methods per class (WMC), Coupling between object classes (CBO), Depth of inheritance tree (DIT), Lack of cohesion of methods (LCOM) [7].
 
 
WMC metric can be taken the aggregation of complexities of the interactive activities of a composite LO which could be used as a predictor for the reusability of the LO. LOs with large number of interactive activities are likely to be more application specific limiting the possibility of reuse. This type of LO should be reconsidered to redefine the functionality.
DIT metric is the count of depth of LO in the framework. LOs that are deeper in the framework are more complex and application specific,thus less predisposed to reuse.
CBO metric is the count of the number of LOs to which the one under consideration is coupled. High number of relationships to other LOs entail that the LO is not self contained and hence less reusable. Coupling of such module should be decreased somehow.
LCOM metric measures disparateness of objectives (as stated in metadata records) for the activities that are part of a LO are indicators for ill define objectives and hence hampers reuse driven by particular LO.
Conclusion
Reusability in the e-learning material is applicable with the help of concept of learning objects. Granularity along with coupling, cohesion and complexity is a measure factor to determine the reusability level of a particular LO. Various metrics from traditional software engineering can be well implemented for this purpose.

References
1.    William B. Frakes and Kyo Kang, (2005)“Software Reuse Research: Status and Future,” IEEE Transactions on Software Engineering, Vol. 31, No. 7, July 529.
2.    Won Kim, Cyber Database Solutions, Austin, Texas, USA, Timothy K. Shih, Department of Computer Science, Tamkang University, Taiwan on “Reusability and Interoperability for Distance Learning”, journal of object technology.
3.    David A. Wiley, II, “Connecting learning objects to instructional design theory:A definition, a metaphor, and a taxonomy”, Utah State University, Digital Learning Environments Research Group, The Edumetrics Institute, Emma Eccles Jones Education 227, Logan, UT 84322-2830 (435) 797-7562, dw2@opencontent.org.
4.    Mohan, P. (2004a), (2004) “Design issues for building reusable digital learning resources”, International Conference on Education and Information Systems: Technologies and Applications, Orlando, Florida, USA, July 21-25, 171-176.
5.    Duncan, C. (2003), Granularization. In A. Littlejohn (2003) (Ed.), “Reusing online resources: A sustainable approach to e-learning”, London: Kogan Page.
6.    Permanand Mohan1, Sandra Bucarey2, “Designing Learning Objects for Reuse: Experiences with a Software Engineering Course”, 1The University of the West Indies, Trinidad and Tobago, 2Universidad Austral de Chile, Chile.
7.    Juan-Jose Cuadrado1, Miguel-Angel Sicilia2, “Learning Object Reusability Metrics: Some Ideas from Software Engineering”, 1University of Volladolid, Spain, 2University of Alcala, Spain.
 
 
45
Future Computer And Communication: Our Dream: Actually Fictions

Abhinandan Bhunia
Abhirup Bhunia

1.     Introduction: Scientific research has conclusively established that man is a part of nature. While the aim of science is to find answer to “why nature is like as it is” or “what makes nature as it is”; the technology apparently speaking or as is told aims to address the application of science for sustainable growth and development. In this process technology changes leaps and bounds. But over the recorded history of technological changes, the pace at which information technology(IT =Computer + Communication) has changed over last half of 20th century is un precedent. One of the reasons for such rapid growth may be that with this technology human intelligence finds a source of recreating him or her some noble parts. The several empirical laws correlate this un precedent growth of IT. The laws of Computing are: Joy’s law which states that the computing power, expressed in MIPS (Millions of Instructions Per Second), doubles every 2 years, Moore’s laws that state that (a) the number of components on an IC would double every year (this is the original Moore’s law predicted in 1965 for the then next ten years), (b) the doubling of circuit complexity on an IC every 18 months (this is known as revised Moore’s law), (c) the processing power of computer will double every year and a half (Moore’s second law which closely resembles to Joy’s law) and Law of “Price and Power” that states that over the years the computing, processing, storage and speed up power of computers will continue to increase whereas the price of computers will continue to fall. The laws of communication are: Ruge’s law that estimates that the communication capacity necessary for each MIPS is 0.3-1Mbps (Million of Bits Per Second) and Metcalfe’s law which states that if there are ‘n’ computers in a network, the power of the computers in a network like Internet is multiplied by ‘n’ square times. If these laws are any guiding paths for future technologies of Computer and Communication, there remains only one dream of these technologies: theses technologies will touch human axis at relative parameters if not on absolute terms. However most of the wonderful achievements in science and technology are not without their predecessors’ in form of Science Fiction. Logically it is hard to find clear and precise line of demarcation between fiction and vision. In this paper we like to highlight the future of computer and communication in form of fiction.

2.    A few Fiction and Realities of Science: Way back in 1979, the great visionary Dr Arthur C Clarke wrote a novel “The Fountains of Paradise” on a space elevator. Like the elevator you use in air port to move up and down, like the one such you often use in modern multistoried super market, space elevator is to make you move between space and earth, earth and moon, earth and mars, mars and moon. Think of enjoying it your kids in summer or winter vacation. The thought of such fascinating whisking between space and planets was dreamt more than a century ago by Konstantin Tsiolkovsky, a Russian scientist. Making of a space elevator is a simple idea. An orbiting satellite and the earth will be connected by a cable in carrying vehicle up and down.
The technological challenge is to design very rugged cable of huge length. If the satellite is geo stationary, the cable length will be twice the orbit height that is 36,000 km approximately. The cable will be strong not only to carry vehicles up and down but to carry its own weight also. In 1991 carbon nano tubes were discovered. Carbon nano tubes are tiny molecular –scale threads of carbon atoms. It is believed that these tubes are suitable to design the space shuttle cable. But the amount of nano tubes required to design a cable thread is not readily available, neither so

*Lecturer, Department of Electrical Engineering, DREXEL University, USA
*Lecturer, Asutosh College, Kolkata
technically so easy to design. The ruggedness required for space cable is much higher than that is available with so far produced nano tubes. Problem is not just of getting suitable cable thread. How to power the lift? Bettery power is out of question because of time required to carry the lift. Carrying fuel or battery on vehicle will tremendously increase the load that the cable may not sustain. Then comes how to manage the space debris left over when launched over years. These technical problems need solutions before a successful take off. The dream is now however taking a shape towards reality. In fact, two projects are already taken up to implement space elevator. These are LiftPort and x-Tech projects. The project cost may be well around US$10 billion. To encourage the projects, the US space agency, NASA has announced an annual competition with a prize fund of US$ 400,000. It is expected that the project may get a shape around 2015-20.

3.    What is there in Computer: Electromechanical and electronics computers were developed as mathematical tools to support huge quantitative and mathematical works of specialized nature. Before that, this exercise was the prerogative of human being. Once human intelligence finds there are mechanisms that can help them out in exercising their analytical work, temptation leads them to go for next step:  seeking a tool for helping them in performing intelligence exercise. Scientists begin to think of intelligence machines by virtue of which ideas of “Brainy Computer”, “Chemical Computer”, “Bio Computing” and finally ”Quantum Computer” have cropped up. With quantum and bio computing, the radical changes in technology are noticed: from application of mathematics and electrical circuit in computing to application quantum laws of physics and that of biological laws in computation. History of science and technology showed us that no idea ever evolved has gone to ruin. People’s dreams of going to moon and furthest stars once though of science fictions today are just reality. Moreover there is no theory to prove that intelligent person can not design an intelligent machine. Thus I have a high dream that future computer technologies will be intelligent machine at par with human being even they will be of talking and thinking types. They will be bio technology based computers made of bio chips by which people will fail to resist temptation to use bio computing CPU/chips to enhance his memory and intelligence. If philosophy and literature is any guide to future demand of technology, we have the Bharat Ratna and Oscar Winner Satyajit Roy’s famous cinema/film “Hirak Rajar Dehse” (in the land of King of Hira). The “brain washing machine” developed by a scientist was used by king to change the thinking power of farmers. Future may witness similar type of dreamy computers’ exploitation by super powers. Remember: great machines & technologies, super powers and kings always support for their benefits. This trend will augment the evolution of dreamy technology I have thought of as mentioned above.



4.    What is there in Communication: What is communication? What a baby is born, what he does is nothing but a sort of communication. This acoustic and human natural communication has several interesting aspect: It is wireless and it uses single identification for everywhere & anywhere. If the baby’s name is “Bob”, he is called by Bob for any sort of communication and anywhere whether he is in USA or in New Delhi. For the purpose of communication his name is not changed. This means a connection of people, not of machine. With telephony, connection is wired and connection is made to geographic locations where telephone sets are kept. With mobile we tend a little towards human natural communication; as with mobile connection is wireless and connection to mobile machine. But even then your mobile number changes from country to country, no personal single identification you can use over world unlike single identification for example “Bob” in human communication. Technology now is being thought of to provide UTN(Universal Telecommunication Number) so that with single identification number one can communicate world over. Thus it is imperative to say that communication is evolving to become human like communication world over. Today communication trend is “fast is first”. High speed electrical communication is the crying need of the hour. No delay in communication tolerable like that in natural human communication. Life is fast, world is fast, communication must be fast be it satellite, mobile, telephone. But how much fast? At least we are limited by the highest speed that of light. I have a dream. Once the Great Akbar asked his Naba Ratnas: What moves fast? While eight of nine Ratnas pointed towards Royal horse, ninth Ratna, Birbal got an edge over others by saying that “Our Mind, Sir.” With the way technology is being evolved I have every reason to dream of a communication technology like human natural communication with mind moving speed. As of today we have heard of knowledge management with today information technology, I dream of tomorrow’s conscious management with my dream of human like Computer and Communication Technology.

5.    Conclusion: Tagore once told “we have only one country in this universe, and that is world.” Noble Winning Poet Rabindranath Tagore’s such a powerful philosophy may ultimately realize , Cerf, father of Internet has already started a project of inter space and inter star Internet….moving ahead any boundary. We dream of computer and communication technology to lead us to a age when one person may move from one planet to another planet for nosiness, agriculture, education and diplomacy etc, and that too may be with space elevator.

6.     References:
1.    Arthur C Clarke, (1960) The Challenge of the Spaceship.
2.    Arthur C Clarke, A space Odyssey, 1968-2001
3.    Arthur C Clarke, (1980) Myterious World.
4.    Scott Burleigh et al, Interplanetary Internet, (2002) 53rd Int’l Astronautical Congress, The World Space Congress’ Texas, pp 1-9
5.    Toby Howard, The Interplanetary Internet, http://www.cs.man.ac.uk
6.    Kelvin Fall, (2001) Thoughts on the Current IPN Architecture Proposal, Intel Research Document, 2001, Berkeley, CA