APPLYING LESSONS OF OBJECT-ORIENTED SOFTWARE ...

Session F4E INSTRUCTIONAL DESIGN BASED ON REUSABLE LEARNING OBJECTS: APPLYING LESSONS OF OBJECT-ORIENTED SOFTWARE ENGINEERING TO LEARNING SYSTEMS DESIGN Ian Douglas1 Abstract  There is currently a lot of interest in the concept of learning objects. Learning objects are discrete units of learning resources based on agreed standards. The idea behind learning objects is to promote greater reuse of resources within new instructional systems development. The main work in learning objects has primarily focussed on defining the technical requirements and standards for computer based learning objects. The technology itself is not likely to bring the benefits promised by reusable objects without a change in methods used by practicing instructional designers. The instructional design implications of the learning object approach is examined to determine the adaptation required in instructional design methodologies. Object-oriented software engineering is proposed as a useful basis for new thinking in instructional design methodology. Index Terms  learning objects, reuse, instructional design, methodology.

INTRODUCTION Prior to the industrial revolution, a craft based approach to product manufacture was prevalent, where one or two individuals would create a complete product from the raw materials available to them. The industrial revolution brought about major changes to the way products were manufactured. Among the major developments were the division of labor, increased automation and the development of the component based approach to manufacturing. In component-based manufacture, specialist producers develop and construct products (e.g. automobiles) from collections of more general components produced by specialist suppliers (e.g. tires, nuts, and seats). The chief benefit of a component type approach is allowing reuse; i.e. a component used on one product can be used to provide the same function for another product. The speed of new product development is increased as new products are assembled from different combinations of existing components. Incremental improvement is also possible, as new and improved components become available. A parallel to the industrial revolution has occurred within a shorter time frame in the software industry. It is

only since the development of the idea of software engineering in the 1970’s that software development has begun to move from a craft to an industry. Although a craft like approach is still prevalent, the use of multidisciplinary teams using a systematic development process and automated tools is becoming more common. The development of object-oriented programming has promoted the cause of software reuse, and this has led to the development of reusable component technologies [1,2,3,4]. This paradigm shift in computer software development is changing how people think about software design. Designers will think first and foremost about what components already exist for the functionality that they wish to achieve rather than seeking to craft a whole application from their own coding efforts. The web has facilitated this reuse through the creation of a number of repository sites where components can be exchanged [examples include 5,6,7]. The idea of moving to a component model for development of courses and content has gained prominence more recently and been driven by the interest in the educational potential of the Internet [8]. There are now a number of initiatives, which seek to transfer the ideas and benefits of the component approach to the development and delivery of educational systems [9,10,11,12]. The idea is also of interest in the commercial training world [13,14]. A learning component, more commonly referred to as a learning object [14], is any discrete unit of learning material that can be extracted from one course and integrated into another. Existing learning materials might appear to be composed of learning objects, e.g. chapters in a textbook. However, a book chapter would only qualify as a reusable object if it were digitized, not integrated through crossreferencing to other chapters and had a metadata attachment. The majority of current learning materials such as textbooks and computer-based instruction are designed as large integrated packages rather than as collections of small independent components that can be individually used and modified for multiple purposes. Reusable learning objects is an emerging paradigm shift in instructional systems that promises to bring to education the same improvements in productivity that it has in software development. There are a number of problems to be resolved before component manufacture becomes an established approach in educational systems design. These

1 Ian Douglas, Florida State University, Learning Systems Institute, Suite 109, Morgan Building, Innovation Park, Tallahassee, Fl 32306, [email protected]

0-7803-6669-7/01/$10.00 © 2001 IEEE October 10 - 13, 2001 Reno, NV 31st ASEE/IEEE Frontiers in Education Conference F4E-1

Session F4E include the issues of standards for learning objects, access to learning objects and support for those educators making the transition to object based design.

LEARNING OBJECT STANDARDS The main problem with current learning technologies is that they are held back by proprietary standards. Thus content authoring systems create content that will not run appropriately under many learning management systems and learning management systems can only cope with certain kinds of learning content. This limits the market for exchangeable content. The problem of standards will be resolved by either of two means. The market will determine the standard, or an organization that is supported by the majority of developers will set a standard. There are now a number of organizations involved in specifying standards for learning objects. In addition to ensuring common standards for the packaging and operation of computer based learning objects across a range of authoring systems and learning management systems, standards groups have also been concerned with a number of other issues. One particular area where much work has been done is in the metadata requirements for learning objects. A foundation for many standards efforts in metadata is the Dublin core [9], which is a widely accepted proposal for core metadata to be attached to web based resources. It is intended that this metadata will be useful in supporting resource discovery on the Internet by providing a standard set of descriptors for those resources. The IEEE Learning Technology Standards Committee (LTSC) has developed in cooperation with others, a standards specification for learning object metadata [11]. The specification incorporates the Dublin core within its framework and defines eight meaningful categories of descriptors: • • • • • • • •

General: context independent features of the resource including its Identifier, Title. LifeCycle: features related to the life cycle of the resource like its Version or Status. MetaMetaData: origin and edition of the metadata. Technical: technical features of the resource like Format (technical data type of the resource). Educational: educational or pedagogic features of the resource. RightsManagement: features that need to be interpreted according to the use of the resource. Relation: features of the resource in relationship to other resources. Annotation: comments on the educational use of the resource.

Instructional management system (IMS) [10] is a consortium of organizations, including universities and technology companies, which is concerned with developing standards in a number of areas relating to learning objects. In addition to its involvement in learning object metadata specification, IMS is also involved in the following: •

Enterprise standards for sharing data about learners, courses, performance.

•

Content Packaging: The means to describe and package learning materials into interoperable, distributable packages. Question and Test Specification: Sharing between different assessment tools. Learner profiles specification for holding information about the learner that a learning management system can use.

• •

Other organizations involved in developing standards for learning objects include the - Aviation Industry CBT Committee (AICC) and the US Department of Defense’s Advanced Distributed Learning (ADL) initiative. The Sharable Content Object Reference Model (SCORM)[12] has arisen from the ADL initiative and was developed in collaboration with IMS, AICC and IEEE LTSC. The SCORM is intended to promote reuse among the military training community. The current version of SCORM covers three areas: the course structure format for object based courses, the run time environment for accessing learning objects, and content metadata.

OBJECTS REPOSITORIES Once a standard has been established, the next problem is to create a system whereby standard objects can be accessed and exchanged. This will be achieved through the creation of learning object repositories either locally for intraorganizational sharing or on the Internet for general exchange. Course developers will use a repository to obtain preexisting learning objects and developers of learning materials will use it to share their objects. Repositories also have a role in assisting developers decisions regarding the need for new content, e.g. areas where there are few or no learning objects and areas where there is a need for learning objects supporting different learning models, or newer technologies. Early initiatives on repositories of learning resources are EOE and MERLOT [15,16,17]. The Multimedia Repository for Learning and Online Teaching (MERLOT) is an initiative of the California State University. It is open to any educator to submit, use, comment on or review learning content submitted to this site. Educators can also register as collaborators in a specific topic area. In this respect it is more than just a repository as it seeks to create an on-line community of developers.

0-7803-6669-7/01/$10.00 © 2001 IEEE October 10 - 13, 2001 Reno, NV 31st ASEE/IEEE Frontiers in Education Conference F4E-2

Session F4E There are a number of different possible models for how a repository can operate. Firstly, in terms of access to resources, learning management systems may directly link to a repository, alternatively, users may be required to download materials to a local server. Secondly, in terms of access rights, the repository may facilitate free exchange (as with MERLOT) or purchase/licensing of materials. Thirdly, in terms of modifiability, resources may be used without alteration or be open to modification. In terms of computer based learning materials, this would require an open source approach, where developers make available the source code of their objects to allow other developers to customize and enhance the objects. Finally in terms of subject matter, repositories can be specific to a certain subject area or specific to an education level or cover a wide range of subjects and levels.

In the model illustrated, after requirements have been analyzed, the first step is to look in repositories for existing resources that may be used or adapted to meet these requirements. Most traditional methodologies do not include such an activity explicitly. Another important part of this model is that any new objects that have to be developed are entered into the repository and that the repository serves as a market through which specialist independent developers can “sell” new or improved resources. The end result of the process is not a finished product but a version of a product that will be continually upgraded by iterating through the process to add new requirements and to discover better components.

Identify Functional Requirements

Evaluate Use if resource object is available

OBJECT BASED INSTRUCTIONAL DESIGN Standards and repositories set the technological framework necessary for a component based approach to educational product development. In addition, efforts are needed to prepare and assist instructional designers in utilizing this technology. Educators need to start thinking in terms of learning objects both when they design and upgrade courses or when they create new learning materials. This involves a paradigm shift from what is currently a predominantly craft based approach to educational product development, which currently has few standards and much duplication of effort. Design thinking needs to move from an approach that is oriented towards creating large integrated packages (e.g. textbooks, CBT) to one that is built around collections of specialized, reusable and granular components. In most conferences and publications on educational technology there is a primary focus on implementation, there is relatively little attention paid to the analysis and design that should precede implementation. There is some work that attempts to focus educational thinking towards systematic approaches to analysis and design [19,20]. This work has served professional instructional designers and educationalist for many years. However, the thinking in this area needs to be updated to provide a framework for analysis and design of instructional systems using reusable objects. It has been noted that existing models of instructional design have been influenced by software development methods, indeed one criticism is that they are primarily linear, based on the waterfall model that was prevalent before software development moved to more iterative and object-oriented approaches. The model illustrated in figure 1 is typical of a more modern approach to software development, with a specific focus on reuse and assembling systems from existing resources (which can include components, open source code or class libraries). The repository plays a central role in this model as the place where all developers store new or improved resources.

Look for resource that satisfies requirements

Modify if resource is close to requirement and is open source

Query

Design and build if resource is not

Resource Repositories

Test Add resource

Add resource

Test

Assemble resources into system

Test

Independent Developers

Version of the Product

FIGURE. 1 LIFE CYCLE FOR AN OBJECT/COMPONENT BASED DEVELOPMENT PROCESS.

In addition to new thinking on the process of development, there is scope for adapting analysis and design methods from object-oriented software design. A popular approach is to make use of modeling notation to facilitate analysis and design thinking. The only thing currently akin to a modeling notation in education is concept mapping [21]. There is scope for making use of a modified version of the unified modeling language (UML) [22] for the analysis and design of courses utilizing reusable learning objects. In particular, use case modeling [23] is easily adaptable to analyzing the performance requirements for students completing a course of instruction. In software

0-7803-6669-7/01/$10.00 © 2001 IEEE October 10 - 13, 2001 Reno, NV 31st ASEE/IEEE Frontiers in Education Conference F4E-3

Session F4E development, use case analysis would lead to other forms of analysis using further UML diagrams, e.g. class diagrams. These other parts of UML are not directly translatable to what is required for modeling learning objects but could form the basis for an educational specific notation. Brerton and Budgen [24] have reviewed a number of issues relating to the design of software components Many of these issues are of relevance to learning object technology. In particular, there is a need to consider granularity in relation to the design of objects. Traditional instructional designers may tend to gravitate towards large objects, while smaller objects are required for maximum reuse potential and flexibility. For example, a learning object may include a discussion of a concept, an example of the application of the concept and a problem to test the users understanding. If instead of being designed as a single object the same material were divided into three objects it would provide greater flexibility to other developers. For example, a potential user may like the explanation of the concept but consider the example to be culturally biased or subject specific and therefore use only the parts that appeal to them. Alternatively, another potential user may be happy with all the content but wish to sequence the objects such that students are tested before seeing the example. There may be the need for designers to identify specialist types of objects in a similar manner to the way software system designers will identify boundary, entity and control objects. Current design thinking for computer based instruction tends to integrate the interface with the content and the content with the testing. Instructional designers new to the object-oriented paradigm will need support and guidance on the kind of issues presented above. As with software development some form of automated support could prove useful.

COMPUTER ASSISTED SUPPORT FOR OBJECT BASED INSTRUCTIONAL DESIGN

There are a now a large number of software tools that assist in the implementation of automated instruction and a number that manage the delivery of instruction via the web. There are relatively few studies and tools relating to the systematic analysis, design and documentation that should precede construction and delivery, and none that incorporate the emerging object model. There is scope for creating the equivalent of computer aided software engineering (CASE) tools for object based instructional design Spector and Muraida [25], Goodyear [26] and Kasowitz [27] review much of the previous work in automated design support tools. Spector and Muraida [25] note that there is strong motivation to develop such tools given there is “a lack of instructional design expertise, pressures for increased productivity of designers, and the need to standardize products and ensure the effectiveness of products.”

Goodyear [26] categorizes the previous research work on automated instructional design as falling within four main approaches. Firstly, there are advisory tools aimed at providing novice designers with instructional design expertise. Secondly, there are procedural support tools. These are “unintelligent” performance support tools such as checklists and templates. Thirdly, there are design annotation systems that allow representation of design thinking, facilitate reuse of design elements and help a design team co-ordinate its activity. Finally, there are generative systems, which can automatically generate an instructional activity from a given specification. All the tools referred to in these reviews are based on the traditional models of instructional design and were mainly experimental; there are very few commercial products of this type. One prominent example of a commercial tool to assist design is Designer’s Edge [28]. In contrast to this situation, there is now a range of tools designed to assist with object-oriented software design and some of the thinking embedded in such tools could be used to create new tools to support object-oriented instructional design.

CONCLUSION The current efforts to set up standards and technological infrastructure for learning objects and learning object repositories promises to provide efficiency gains in instructional development. In particular, it could lead to faster development and better quality, through the market forces facilitated by object repositories. In order for such gains to be fully realized, the technology development needs to be complemented with new thinking among instructional designers. Educators from the field of systems and software engineering have a role to play in developing instructional design methodology relating to learning objects. There are a number of areas where work in object-oriented software analysis and design can be leveraged for the benefit of new instructional design approaches. Specifically, work in modeling notations and CASE tools can be adapted to the needs of object oriented instructional system design.

REFERENCES [1] Herzum P. and Sims O., Business component factory. New York: John Wiley and Sons, 2000. [2] Leavens, G. T. and Sitaraman, M., Foundations of componentbased systems, Cambridge University Press, 2000. [3] Allen, P., Frost, S. and Yourdon E., Component-based development for enterprise systems” : Applying the Select Perspective, Managing Object Technology Series, No 12, Cambridge University Press, 1998.

0-7803-6669-7/01/$10.00 © 2001 IEEE October 10 - 13, 2001 Reno, NV 31st ASEE/IEEE Frontiers in Education Conference F4E-4

Session F4E [4] Szyperski C., Component software: Beyond object-oriented programming, Addison-Wesley. Reading, Mass, 1998.

[18] MERLOT, California Virtual Campus Learning Object Libraries. http://merlot.csuchico.edu/Home.po

[5] Earthweb developers directories. http://developer.earthweb.com/directories/

[19] Dick, W. Carey, L.and Carey, J., The systematic design of instruction. 5th ed., New York: Longman, 2001.

[6] Componentsource. http://www.componentsource.com/

[20] Bruce L.R. and Sleeman, P. J. , Instructional Design: a primer. Greenwich, CT : Information Age Publishing, 2000.

[7] The Active X resource center. http://www.active-x.com/ [8] Roschelle, J., Kaput, J., Stroup, W. and Kahn, T.M.., “Scalable integration of educational software: exploring the promise of component architectures”, Journal of Interactive media in education, volume 6, 1998, www-jime.open.ac.uk/98/6 [9] The Dublin Core Meta-Data Initiative. http://purl.oclc.org/dc/groups/index.htm

[21] Gaines B. R. and Shaw M. L. G., “Web Map: Concept Mapping on the Web”, Proceedings of the fourth international World Wide Web conference, Vol 1, issue 1, 1996. http://www.w3j.com/1/gaines.134/paper/134.html [22] Booch, G., “UML in action”. Communications of the ACM. Vol. 44 No 10., 1999, p 26-28.

[10] IMS (Instructional Management Systems) Project from Educause. http://www.imsproject.org/

[23] Rosenberg, D. and Scott, K., Use Case driven object modeling with UML: a practical approach, Addison Wesley Object Technology Series,1999.

[11] IEEE Learning Technology Standards Committee (LTSC). http://ltsc.ieee.org/

[24] Brereton, P. and Budgen, D. , “Component-based systems: a classification of issues”. IEEE Computer, Vol 33, No 11., Nov, 2000.

[12] ADL Sharable Courseware Object Reference Model, SCORM http://www.adlnet.org/

[25] Spector, J. M. and Muraida, D.J. , “Automating design instruction”. In S. Dijkstra, N.Seel, F. Schott and Tennyson, D. (eds) Instructional Design: International Perspectives, Vol. 2, Mahwah, NJ: Lawrence Erlbaum. 1997.

[13] Bassi, L., Cheney, S., and Lewis, E. , “Trends in workplace learning: Supply and demand in interesting times”, Training and development, Vol. 52, No 11., Nov, 1998, p 51-62. [14] Clark, R.C., “Recycling knowledge with learning objects” Training and development, Vol 52, No 10., Oct, 1998, pp. 60-63. [15] Online educational resources for Physics teachers. http://www.ba.infn.it/www/didattica.html [16] Clark, D.J.M. “Developing, integrating, and sharing Web based resources for materials education”. Journal of the Minerals, Metals and Materials Society, Vol. 50, No 5., May, 1998. http://www.tms.org/pubs/journals/JOM/9805/Clark/

[26] Goodyear, P. ,“Instructional design environments: methods and tools”. In S. Dijkstra, N.Seel, F. Schott and Tennyson, D. (eds) Instructional Design: International Perspectives, Vol . 2, Mahwah, NJ: Lawrence Erlbaum, 1997. [27] Kasowitz, A. , “Tools for automating instructional design”. ERIC clearing house in Information Technology in Education. Syracuse, NY, 1997. http://www.ed.gov/databases/ERIC_Digests/ed420304.html [28] Designer’s Edge. Mentergy. http://www.mentergy.com/products/authoring_design/designer/

[17] Educational Object Economy. http://www.eoe.org

0-7803-6669-7/01/$10.00 © 2001 IEEE October 10 - 13, 2001 Reno, NV 31st ASEE/IEEE Frontiers in Education Conference F4E-5