DesignandreusabilityoflearningobjectsinanacademiccontextAneweconomyofeducation

1、design and reusability of learning objects in an academic context: a new economy of education?submitted to elearning: una sfida per luniversita, milan, november 12, 2002by stephen downes, national research council, moncton, canadacontents1. introduction2. the state of the art3. problems and issues4.

2、 design principles5. the distributed network1. introductionthe purpose of this paper is not to discuss the creation and use of learning objects per se but rather to look at systems for locating and distributing learning objects. what will be argued is that this system is currently poorly constructed

3、, based essentially on what may be called a silo model of distribution. a series of problems and issues related to this model will be discussed. in place of the silo model, a distributed model of learning object repositories is proposed. this model is based on a set of principles intended to create

4、an open and accessible marketplace for learning objects, in essence, a learning object economy. to conclude, a model for a distributed learning object repository network is proposed.for readers unfamiliar with the concept of learning objects, the generally accepted definition is that learning object

5、s “any entity, digital or non-digital, which can be used, re-used or referenced during technology supported learning.” (ieee, 2002) wiley (2000) defines a learning object as “any digital resource that can be reused to support learning.” even so, as wiley comments, “the definition is broad enough to

6、include the estimated 15 terabytes of information available on the publicly accessible internet.” in this paper, a functional definition of learning objects is employed: a learning object is anything that is exchanged in what may be called the learning object economy.2. the state of the artoverviewi

7、n this section common methods for locating and retrieving learning objects will be discussed. in particular, three major systems will be described: course portals, course packs, and learning object repositories. in addition, systems for collecting and organizing learning objects, learning management

8、 content systems, will also be described.course portalsa course portal is a website offered wither by a consortium of educational institutions or a private company working with educational partners that lists courses from a number of institutions. the purpose of a course portal is to enable a studen

9、t to browse through or search course listings to simplify the students selection of an online course. the following are examples of course portals.· teleeducation. a new brunswick, canada, learning organization, teleeducation nb hosts the telecampus online course directory. courses are submitte

10、d by institutions and screened to ensure that they are fully online. the database contains more than 50,000 courses, including about 3,000 free courses and 1,200 complete and fully online programs. telecampus provides a subject-based directory and search services. http:/teleeducation.nb.ca/· un

11、ext. focusing on business education, unext collaborates with major business schools such as the columbia business school, stanford university and the london school of economics to provide courses in leadership and management, e-commerce, marketing, finance, accounting, and business communications th

12、rough the private and for-profit institution, cardean university. · hungry minds. hungry minds offers more than 17,000 courses through its online campus, hungry minds university, from course providers such as the university of california at berkeley, the university of california at los angeles

13、and new york university. hungry minds also provides learning content through publishers such as for dummies, cliffsnotes, and frommer's. · fathom. created by columbia university and including partners such as the university of chicago, the london school of economics and political science, c

14、ambridge university press, the british library, the smithsonian institution's national museum of natural history, and the new york public library, fathom is a centralized for-profit learning object repository. while fathom provides lectures, interviews, articles, performances and exhibits, its m

15、ajor focus is an offering of online courses from member institutions. (you, 2001)course packscourse packs are packages of learning materials collected to support a course. offered primarily by educational publishers, course packs are collections of learning materials offered to instructors for use i

16、n traditional or online courses. the course pack may be pre-defined or custom built by the instructor. the instructor is expected to supplement the course pack with additional content, educational activities, testing and other classroom activities.some course packs, such as those offered by xamedu,

17、are stand-alone. this means that the course pack is distributed as a separate product and purchased by the student directly through the college or university bookstore. supplementary educational materials are offered by the instructor on his or her course website or are delivered in a classroom sett

18、ing. other course packs are available for use only in a learning management system (lms). course packs delivered through a learning management system are more like default online courses. using tools provided in the lms, the instructor selects the course and customizes it for delivery online.the fol

19、lowing are examples of course pack providers:· webct course packs. the learning management system webct offers course packs consisting of a course structure and set of readings offered by publishers with a distribution agreement with webct. course packs are purchased by the institution on a sea

20、t-license basis and are then customized by the instructor.· canadas schoolnet. in canada, the leading learning resources portal is probably canadas schoolnet. a list of resources is displayed, each with a short description and a link to an external website. schoolnet also provides information a

21、bout each site and provides an “advanced search” using metadata. each resource in the “curriculum” area is approved by a professional “pagemaster”. for the most part, however, schoolnet links to institutional home pages, and not to learning resources per se. teachers using the schoolnet service must

22、 still search through these sites in order to locate suitable materials. http:/www.schoolnet.ca/ · marcopolo. marcopolo is a compilation of teaching resources from six educational institutions which provide free internet content for k-12 education. what the six partners have in common, and what

23、 makes this an important and interesting development in online learning, is an adherence to national curriculum and evaluation standards in the subject areas. material is categorized by grade level and individual items are matched to individual learning topics. despite its strengths, however, marcop

24、olo is a closed project; only the six member institutions contribute content. there is no centralized search facility and no metadata listings for the resources. · xanedu. xanedu is a learning resource site that collects articles from journals, magazines and other resource providers. instructor

25、s may compile course packs consisting of collections of these materials; students who subscribe to xanedu may access these course packs. the materials are sorted by category and may also be located using a search mechanism. like marcopolo, however, xanedu is a closed project. it draws materials only

26、 from selected publishers. and while it allows subscribed students to browse through its materials, the vast bulk of resources available on the internet cannot be found through xanedu. learning object repositorieslearning objects are stored in databases called learning object repositories. there are

27、 two major types of repositories: those containing both the learning objects and learning object metadata, and those containing metadata only. in the latter case, the learning objects themselves are located at a remote location and the repository is used as a tool to locate learning objects. in the

28、former, the repository may be used to both locate and deliver the learning object.most learning object repositories are stand-alone. that is, these repositories function a lot like portals in that they contain a web-based user interface, a search mechanism, and a category listing. another major clas

29、s of learning object repositories functions more like a database attached to another product. an lcms, for example, may contain a learning object repository intended for its exclusive use.two major models for learning object repositories exist. the most common form is a centralized form in which the

30、 learning object metadata is located on a single server or website (the learning objects themselves may be located somewhere else). an alternative model is the distributed learning object, in which the learning object metadata is contained in a number of connected servers or websites. distributed le

31、arning object repositories typically employ a peer-to-peer architecture to allow any number of servers or websites to communicate with each other.the following are examples of some learning object repositories: · merlot. described above, merlot is probably the most well known learning object re

32、pository. merlot is a centralized repository containing metadata only and pointing to objects located at remote locations. it is stand-alone, acting like a portal for learning objects. in addition to providing search and categorization, merlot provides a peer review service provided by communities o

33、f experts in different subject areas. · campus alberta repository of educational objects. careo is a centralized collection of learning objects intended for educators in alberta, canada. a stand-alone repository, careo contains metadata and provides access to learning object

34、s located on remote web servers. · portals for online objects in learning. pool is a distributed (peer-to-peer) repository system under development intended to create a pan-canadian repository of learning objects. a primary objective of pool is to develop and distribute tool

35、s for creating connected learning object repositories. (not currently functioning). see also http:/www.canarie.ca/funding/learning/1999backgrounders/pool.html · national smete distributed library. in development for the (smete), ndsl is intended as a “federation” of learning object repositories

36、, each library using different document formats, different systems of classification, and different database and repository management schemes. ndsl is intended to join these libraries using a common search engine called emerge and a method for sharing resources called love (learning object virtual

37、exchange). (chen, 2001) learning content management systemslearning objects are typically small, consisting of no more than the equivalent of an hour or two of instructional time (there is some debate as to how small a learning object may be and whether educational content must contain pedagogical f

38、eatures, such as a statement of learning objectives, in order to qualify as a learning object). most educational institutions deliver larger chunks of instruction, called courses. to create a course, therefore, a set of learning objects must be assembled into a package. packages organize learning ob

39、jects sequentially. in order to create a course out of, say, a dozen lessons, where each lesson is a separate learning object, a course author arranges these lessons into a sequence. in some cases, where the learning objects are smaller units, course designers may need to create lessons composed of

40、a sequence of individual modules, then the course as a whole out of the sequence of lessons. however created, the sequence of objects is used to define course-specific entities as the course outline or table of contents.packages are created using a learning content management system. while a course

41、author could locate and assemble learning objects by hand, it would be tedious and unproductive to do so. courses created using learning objects are typically created using a development environment called a learning content management system (lcms). the lcms performs two major functions: it provide

42、s authors with a means of locating learning objects, and it assembles them into standards compliant learning packages (or courses). (ellis, 2001)though many types of lcms are available, the typical lcms will contain four essential features: an authoring application similar to the computer assisted s

43、oftware environment (case) described above, a collection of learning objects (called a repository), a means of sending the completed course to a delivery system (called a delivery interface), and administration tools. using an lcms, a course author defines major features of the course: its topic are

44、a, say, or its grade level. the author then instructs the lcms to search through the learning object repository for relevant resources (because the data is in xml, the search can be very precise). from the search results, the author may review a learning object or select it for inclusion in the cour

45、se. the lcms retrieves the object metadata from the repository and inserts it into the course package. the lcms automatically adds institution-specific formatting and prepares the package for delivery.3. problems and issuesoverviewin general the issues surrounding the location, distribution and reus

46、e of learning resources online have to do with system architecture and resource based on what i call the “silo model.” on the silo model, resources are not designed or intended for wide distribution. rather, they are located in a particular location, or a particular format, are intended for one sort

47、 of use only. the silo model is dysfunctional because it prevents, in some essential way, the location and sharing of learning resources. in an important sense, such resources or architectures are broken because they require some additional step, usually involving manual labour, in order for develop

48、ers or learners to make use of the material. the requirement of such a step adds significantly to the cost of a learning resource and in some case may prohibit its use altogether. in fairness, this cost or prohibition may be imposed by design. but from the point of view of a learning object economy,

49、 the resource or architecture is unusable.there are numerous ways a learning resource or architecture may follow the silo model. in this section, a number of these are listed. few products embody all of these problems. but most contain instances of at least one of these problems. and even a single i

50、nstance of the silo model is enough to prevent a learning resource or architecture from being used as part of a network. proprietary standardsa standard is proprietary when it is secret or when patents, copyrights or other restrictions prohibit its use. the standard is created by a commercial entity

51、 and specifies “equipment, practices, or operations unique to that commercial entity.” (national communications system, 1996) with the advent of the internet, proprietary standards are much less of an issue than in years past. nonetheless, proprietary standards continue to abound, especially in the

52、realm of multimedia formats. the use of a proprietary standard divides a distribution network into those people or systems able to use the standard, and those people or systems unable to use the standard. for example, a document created using dxf for autocad may not display properly in cadkey, which

53、 uses cadl, or acis, which uses sat. another example is xrml, a digital rights management language developed by contentguard. developers have been reluctant to use the standard because of microsofts control over the standard. (drm watch, 2002)proprietary standards pose numerous risks to developers.

54、one risk is that the standard will cease to be supported in new software. documents encoded in older ms word formats, for example, need to be converted before they can be used. there is the risk that licensing terms may change, and as a consequence, require that user pay unexpected licensing fees. i

55、f the standard is not widely shared or distributed, as is the case, for example, with microsoft windows, it is difficult to develop new applications, and the holder of the standard enjoys an advantage over competing products. additionally, the choice of viewing software may be limited. because of th

56、ese risks, it is difficult to encourage wide adoption of proprietary standards. several of the systems listed in the previous section depend in whole or in part on proprietary standards. course packs designed for web ct, for example, cannot easily be used in competing learning management systems. it

57、 is necessary to use a content migration utility (some versions of which are no longer supported) to obtain interoperability. overly strict standardseven when a standard is non-proprietary, it may be the case that the standard is too limiting for widespread use. if, for example, a standard requires

58、that only a limited type of data will be transported by a data transmission system, then novel applications using different types of data will be impossible to develop. much of the criticism around the sharable content object reference model (scorm) was focused on this sort of objection. scorm was developed to support self-study modules designed for use by the u.s. military. learning objects defined using scorm are mutually independent, meaning that only the most