EXTENSIBLE LEARNING OBJECTS
Bill Tait
Teaching Fellow, The Open University
Milton Keynes, UK
wht4@tutor.open.ac.uk
ABSTRACT
Learning objects have been around for a long time but are not as widely used as they might be. The reasons are mainly
pedagogical and relate to both the context in which the object is used and its implementation. These are explored in this
paper and a solution proposed in the form of learning objects based on XML technology that allows tutors to edit the
contents. Extensible learning objects are being trialled in a course on an introduction to programming with JavaScript.
KEYWORDS
Learning, object, reusable, pedagogy, e-learning, XML.
1. INTRODUCTION
Learning objects (IEEE, 2002. Wiley, 2002) are sometimes described as reusable learning objects (RLO).
They are reusable in different contexts because they address easily identifiable learning objectives and do not
interact substantially with the rest of the course. These properties are sometimes referred to as high cohesion
and low coupling (Boyle, 2003), or abstraction and encapsulation, and are illustrated in Figure 1. They mean
that an object is not only reusable but, conversely, it is replaceable.
Figure 1. A learning object in a course context showing internal cohesion, in the form of its own internal structure and
learning objective, and external decoupling, in that it is not linked to other units.
The main advantage of reusable objects is economy. They reduce the costs of course development and
time to market. A second potential advantage is quality. If they are obtained from a recognised source they
have probably been exposed to peer scrutiny, which is a form of quality assurance. Another major advantage
is that, because they are replaceable they are easily maintained. They can be updated or changed without any
unforeseen consequences in the rest of the course. And there is a fourth advantage in that they can be web
based and searchable in online repositories (e.g. CAREO, 2007, MERLOT, 2007, MIT, 2007, Intute, 2007,
and Connexions, 2007). In this case, they are more easily discoverable than many other resources.
With all these advantages, learning objects have become a recognised format for e-learning. The
technical standards are well established (SCORM, 2004) and the IMS Learning Design approach (IMS, 2003)
has been developed to include generic learning activities that address pedagogical issues. However, there
remain some problems associated with this aspect and in particular with adapting learning objects to the
course context (e.g. Jones, 2004, Friesen, 2004, Hedberg, 2006). To examine these it is necessary to look at
the underlying properties of learning objects in terms of contextualisation, encapsulation and implementation.
2. CONTEXTUALISATION
An object usually has to support some cohesion in its context. As an example, Figure 2 shows a series of
course modules on JavaScript Programming that have been used in the present study. It refers to a sequence
of objects on familiar programming topics, namely, Decisions, Loops, Arrays and Interfaces. These are
precisely identified by their learning objectives. However, they cannot achieve these objectives unless prior
objectives have been delivered by earlier objects. The Arrays object, for example, uses learning outcomes
from the Loops topic so it can only be reused in a location where that topic has already been covered and the
objective achieved. This is important because, in some courses, these topics are studied in the reverse order.
.
Figure 2. An object-oriented course structure showing the effects of contextualisation, in that learning objects have
defined entry requirements as well as exit objectives.
Contextualisation pedagogy may be related to the need for learners to construct new knowledge by
linking it to existing personal knowledge. Imposing an order in which topics are delivered facilitates learning
and manages the continuity of the learning process. In general, however, if an object is to maintain this
pedagogy it should have specific entry requirements and exit objectives that match those of the context.
3. ENCAPSULATION
In some cases, linking entry and exit objectives may not be sufficient. Practical applications can be
introduced in one part of the course and extended into another one so that progressively more advanced and
therefore more authentic applications can be developed as the learner’s knowledge advances. If this is
allowed, it would mean that objects introduced into a course would have to be aware not only of learning
objectives already achieved but also of how they were achieved. This would tend to reduce encapsulation to
the extent that replacing objects might have wide ranging consequences throughout the course and, in effect,
make these imports unusable.
So if reusability is to be maintained it appears that some sort of compromise is required to cope with the
conflicting requirements of contextualisation and encapsulation. This is also the case in object-oriented
software development where the solution is to link objects by means of their input and output objectives but
to hide their inner processes from each other. A similar solution can be applied to learning objects which
should therefore match entry and exit conditions but not extend any internal processes. It is possible, of
course, to be more flexible and add some practical applications to the learning objectives thereby increasing
the contextualisation at the expense of encapsulation but, in general, there will always have to be some sort of
trade-off between these two concerns.
This need for encapsulation is illustrated in Figure 3. It is a radical departure from the pedagogy of
traditional “procedural” teaching and, in this respect, a negative pedagogy. For example, the Decisions
object in Figure 3 uses authentic practice in the form of the development of a JavaScript calculator. This
cannot be extended in the following Loops and other objects so it is difficult to apply the full power of the
course to extend an application. If a similar one is used later it must be redeveloped from the beginning.
Figure 3. An object-oriented course structure showing the effects of encapsulation. The dashed lines indicate
disallowed links between the contents of objects if full reusability is to be maintained.
4. IMPLEMENTATION
Although the implementation of an object should be hidden from other parts of a course it is still important.
The achievement of its learning objective depends on the way in which the object is implemented since this
has to be suited to the needs of the learner, the tutor and the course. Objects that are effective in one context
may be less so in another.
The implementation of a learning object is determined by the learning method employed, the learning
contents, and the presentation, which together define its internal pedagogy. In Figure 4 the method is defined
by the text on the left and the content is displayed on the right while the presentation is represented by the
overall effect.
Figure 4. An illustration of the implementation pedagogies in a learning object. The text in the left panel describes
the teaching method and the browser simulation on the right is the learning content.
Learning methods cover so many possibilities that it may be impossible to classify them. A practical
approach is to define them in terms of traditional teaching methods and most repositories do just that.
MERLOT, for example, offers Interactive Lectures and Just-in-Time Teaching, while CAREO, provides a
more extensive list of 14 different methods, including Exercise, Simulation, Questionnaire, Diagram, Figure,
Graph, Index, Slide, Table, Narrative Text, Exam, Experiment, Problem Statement and Self Assessment.
Another approach is to define generic pedagogies that can be populated with content objects (Laurillard and
MacAndrew, 2003). This can be extended to the specification of generic learning methods, or learning
activities in resource metadata as in the IMS Learning Design specifications (IMS, 2003). However, these
solutions are not fully context-sensitive and they are not locally adaptable down to the level of specific
learner preferences by practising teachers with little technical knowledge of software course design.
Figure 4 shows a scene from a Tutorial object developed in the present study that uses independent
learning. Here the student is faced with a set of interactive problems followed by answers and explanations.
However, the same material could have been used in an almost infinite variety of methods, for example, with
a concurrent online discussion, a self assessment, or as preparation for, or follow-up to a face-to-face tutorial.
Learning contents are used by the learning methods. They are usually simple learning objects, such as
diagrams or animations, and are employed to illustrate concepts and provide authentic practice. They may
take the form of narrative text but are more often implemented with richer media, such as graphics, images,
audio, video, animations, simulations and various forms of interactive content.
The presentation of an object covers the style, notation, vocabulary and any other features that may vary
from one treatment of a subject to another. It is an almost eclectic mix that corresponds roughly to the user
interface of an object-oriented program. Normally, it is expected to be consistent with the rest of the material
in the course programme. In fact, it should satisfy the course design criteria as well as the principles of HCI
(Human Computer Interface) theory.
The argument for this pedagogy might be that variations in presentation result in students having to
construct superfluous knowledge not associated with the subject being studied. In that case, inconsistency
with existing course materials would be seen as undesirable. There is an alternative point of view, however.
Encouraging learners to deal with different presentations may be seen as satisfying constructivist principles
of multiplicity and authenticity (Tait, 1997), which may be useful in preparing them for lifelong learning
outside academia.
5. REUSABLE LEARNING OBJECTS
Faced with the problems of contextualisation, encapsulation and implementation it is not difficult to see why
some authors have found learning objects to be less than reusable. It is possible to use objects that avoid the
problems. Very large objects such as complete courses or modules (MIT, 2007) can do this by having their
own internal cohesion. But, like books, their contents seldom match the user’s requirements exactly and they
cannot be adapted without substantial rewriting. Another option is to use very small learning objects. These
are reusable and replaceable but are not easily embedded in the course without additional material and do not,
therefore, realise all the advantages of learning objects. Between these extremes, learning objects are not
always directly reusable because of the pedagogical requirements of contextualisation, encapsulation and
implementation.
There are two ways of dealing with the problem. One is to ignore it and encourage students to search the
Internet for relevant materials as part of a self motivated independent learning scheme. This is certainly
active learning, in the true constructivist sense, and can be viewed as a form of discovery learning
(Laurillard, 1995). It usually requires considerable starting knowledge of both the subject and the medium so
it is widely used in project work. However, it does expose learners to the full spectrum of Internet
pedagogies. A more controlled variant is for a tutor to direct students to suitable objects, which is similar to
the practice of recommending textbooks and giving references. Both approaches have their merits but
instead of dealing with the pedagogies they are actually redefining them or, perhaps, just coping with them.
The only alternative to using other people’s objects is, of course, to write your own. For most tutors this
is not an option since they have neither the technical expertise nor the interest in acquiring it. However, it
may be possible to develop objects that can be adapted by tutors and other users, and this has been the aim of
the present study.
6. EXTENSIBLE LEARNING OBJECTS
Some adaptability can be introduced to learning objects by adding hyperlinks which can be edited by the
tutor to direct students to prerequisite objects (Jones, 2004). An alternative and potentially more powerful
solution that is investigated here is to enable more extensive editing in an attempt to deal with all of the
pedagogical problems described above. This approach employs eXtensible Markup Language (XML)
technology to separate content from presentation. In principle, objects can be produced with advanced
development software, such as Flash or Java, but in such a way that their pedagogies are determined by a
separate XML document that is easily edited by tutors. This delivers some flexibility in allowing tutors or
course planners to adapt the objects for specific local situations.
The idea has been examined by developing online tutorial objects for use in a first year course on
JavaScript programming. Each tutorial consists of a series of pages each with a text component, giving
instructions to the students and so defining the learning method, and a simple object representing the learning
content, in this case a simulated program running in a browser. The pages are embedded in a Flash container
with built-in user navigation as illustrated in Figure 5. The text is saved on the web server as a simple XML
document file and the container is saved as a Flash movie. When this is downloaded into a browser the Flash
loads the XML file into the left panel. So the XML file is easily edited without in any way having to access
the Flash file.
Figure 5. An XML document, on the left, combined with a Flash object container, on the right, to provide a page in
a tutorial object.
XML technology can be used to adapt all three pedagogies described above. Contextualisation problems
can be solved by including other objects or references to them and encapsulation can be satisfied with similar
extracts from the contents of other objects or references to appropriate support materials. In this first trial,
however, only the implementation learning method was editable, as the element that most frequently
compromises reusability.
A default version was provided that employed an independent learning method in which the students had
to go through the tutorial by themselves, online and without tutor help except, perhaps, by email. This is
similar in some respects to the exercises provided in textbooks but more powerful in terms of the kind of
content that can be included. The pattern is that they are first shown a problem and asked to solve it before
navigating to the next page where the solution is discussed. They are asked to carry on through the rest of the
tutorial solving progressively more difficult problems on the same theme until, at the end, they can be
assumed to have mastered some specific learning outcome. So it has built-in cohesion and some authentic
progression. It is a common tutorial procedure, apart from the fact that the student can always look ahead
and see the solution. But this, too, is a familiar device, usually known as a Self Assessment Question, or
SAQ. It is the method illustrated in Figure 4 above.
This type of tutorial is a useful learning exercise and a well tried pedagogy but it may not be the most
effective one for the local context. So, a second version offered to the tutors allowed the learning method to
be adapted for use with a concurrent online tutorial. In this version, solutions could be withheld until the
discussion reached maturity, in some ways simulating a face-to-face tutorial.
7. RESULTS
Two tutorial objects were developed and tested in three ways. First they were demonstrated and discussed in
a series of presentations. Then they were published on a website where download statistics and feedback
forms were used to evaluate interest. Finally, they were discussed in a number of follow-up presentations to
obtain further feedback.
One of the initial presentations was to an audience of about 15 tutors drawn from a single region. They
were shown two versions of the tutorials, one for independent learning and the other editable for use with
online discussions. They were all enthusiastic about the software and confident in their abilities to edit the
text for their own use.
The next stage involved the publication of the tutorials on the web. These were offered nationally to all
the tutors involved in the course and, through them, to their students. In order to keep the trial simple, only
the independent learning versions were offered, at this stage, but users were invited to signal their interest in
the adaptable versions.
The site download statistics indicate the extent to which the tutorials were used, the pages that were
accessed and the duration of each session. The evidence from this source is not very accurate since it is not
clear how many students were directed to the site, or how often each one accessed the site. However, some
concrete information can be extracted. For example, the number of recorded sessions was three times the
number of tutors informed. About 10% of these sessions were long enough to read through a tutorial and a
further 10% were long enough to work through it. These figures suggest that the tutorials were at least
interesting to the target audience.
The feedback forms represented a much smaller data sample but they did offer specific opinions. From
these it is clear that the tutorials were regarded as technically and pedagogically successful by both tutors and
students. However on the key issue of adaptability there was a mixed response. The tutors were generally in
favour of being able to adapt them for use with online tutorials but the students were inclined to opt for the
default independent learning versions.
The follow-up discussions and presentations confirmed the interest in the XLO model and raised two
other points. The first is that there is general agreement that some deficiencies in the contextualisation and
encapsulation aspects of learning objects can also be dealt with by editing the implementation text. The
second is that other ways of using XML learning objects might be welcomed. One of these is to provide a
series of templates that will allow the same educational objects to be used in different delivery systems,
thereby, using XML in the way that it was originally intended – for presenting the same content in different
systems. For example, it may be used to deliver text files suitable for printing hard copy for use in face-toface tutorials. And it may be used for m-learning as well as e-learning. In this case, sound files can be used
instead of text to make the tutorials deliverable on the small screens of mobile devices. The result of
adapting the JavaScript tutorial is this way is illustrated in Figure 6.
Figure 6. The JavaScript tutorial delivered in a mobile device.
8. CONCLUSION
The main conclusion of this study is that it is feasible to use XML technology to deliver learning objects
whose embedded pedagogy can be adapted to suit course contexts and tutor preferences. Specifically, it is
technically possible to offer extensible learning objects on a web repository. It is also acceptable in terms of
tutor usability. All that is required is for the designer to separate out some of the content into an XML
document. It is not a difficult task for a Flash or Java programmer to produce adaptable objects such as these
illustrated here. In addition, it is clear that the adaptable objects are easily edited online by tutors with no
particular expertise in the use of software other than a word processor. On this evidence, XLO can be
regarded as a viable design model.
This study was restricted mainly to the independent learning method but it appears that the extensibility
option is of interest to most tutors. This was confirmed by responses to the initial presentation, feedback
from the subsequent web publication and informal discussion following that. These discussions and
presentations are ongoing but they have already produced two further indicators. One is that it would be
equally feasible to use XLO to cope with pedagogical problems related to contextualisation and
encapsulation and the other is that the same technology can be used to adapt the implementations for course
delivery in various formats such as those suitable for printable text and for mobile devices.
REFERENCES
ADL, SCORM 2004 Accessed via http://www.adlnet.gov/scorm/index.cfm (Jan 2007)
Boyle, T. (2003) "Design principles for authoring dynamic, reusable learning objects". Australian Journal of Educational
Technology, 19 (1), 46-58
CAREO, “Campus Alberta Repository of Educational Objects”, Accessed via http://careo.netera.ca, (9 Jan 2007)
Connexions, “The Connexions Project at Rice University”, Accessed via http://cnx.rice.edu, (9 Jan 07)
Friesen, N, (2004) “Three Objections to Learning Objects and E-learning Standards”. In McGreal, ed. Online Education
Using Learning Objects, Routledge.
Gunn, Cathy, Woodgate, Sheila, O’Grady, Winnie, (2005) Repurposing learning objects: a sustainable alternative? ALTJ, Research in Learning Technology Vol13, No 3, pp189-200.
Hedberg, John G. (2006) E-learning futures? Speculations for a time yet to come. Studies. Continuing Education, Vol.
28, No 2, pp 171-183.
IEEE Learning Technology Standards Committee (2002) Learning Object Metadata, Final Draft Standard, IEEE
1484.12.1-2002
IMS (2003). IMS Learning Design Best Practice and Implementation Guide. IMS Global Learning Consortium,
Inc.
Intute, JISC. Accessed via http://www.jisc.ac.uk/whatwedo/services/services_mimas/services_intute.aspx (9 Jan 07)
Jones, Ray. (2004) Designing Adaptable Learning Resources with Learning Object Patterns. Journal of Digital
Information, Vol 6, Issue1, Article No 305.
Laurillard, Diana. (1995) Multimedia and the Changing Experience of the Learner. British Journal of Educational
Technology, Vol 26, No 3, pp 179 – 189.
Laurillard, Diana and MacAndrew, Patrick (2003) “Reusable Educational Software: A Basis for Generic E-Learning
Tasks”. In Allison Littlejohn, ed. Reusing Online Resources: A Sustainable Approach to eLearning, Kogan Page, Ch
7.
MERLOT, “A free repository for higher education”, Accessed via http://www.merlot.org/Home.po, (9 Jan 2007).
MIT OpenCourseWare, developed “to provide free, searchable, access to MIT’s course materials for educators, students,
and learners around the world.”. http://ocw.mit.edu, (Accessed 9 Jan 2007)
Tait, Bill (1997) Constructive Internet Based Learning. Active Learning, No 7, pp1-8.
Wiley, D. A. (2002) Connecting learning objects to instructional design theory: a definition, a metaphor, and a taxonomy,
in: D. A. Wiley (Ed.) The instructional use of learning objects (Bloomington, IN, AIT/AECT), 3_23