Implementing learning object metadata for mobile devices using CanCore
Rory McGreal 
Athabasca University 
rory@athabascau.ca

Abstract

Pedagogical and other types of metadata are important in the implementation of learning systems for use by mobile devices. Metadata is key to the use of learning objects. Learning objects represent a means of rendering learning content interoperable on a wide range of devices in different formats using XML for usability on small and large screens. To ensure discoverability and repository interoperability, metadata is essential. CanCore is a metadata profile for implementing the IEEE LOM, thus advancing the use of learning objects. With enhancements to the profile and to the LOM, providing for location and time, as well as other contextual information, mobile devices can be used effectively as an extension of the global data infrastructure.

B12. National and International Projects on Mobile Learning
1. Introduction
Mobile devices are becoming increasingly more sophisticated. Viewing screens are sharper and more easily viewable, interactive multimedia content can now be displayed; memory storage is increasing; and wireless access is becoming ubiquitous [1-3]. Clyde [4], challenges educators to identify the strategies and means where  learning on these mobile devices are most appropriate taking into account their deficiencies as well as their attributes.
Convergence and divergence of mobile devices are both happening simultaneously. Mobile phones are converging as smart phones with PDA features (e. g. Nokia 9290 Communicator and the Erickson 218 Palmtop). PDAs are converging with telephone capabilities (e.g. Treo and Blackberry). Others are adding features such as video, photos, audio, and gameplayers. Divergence is demonstrated with ebooks (e. g. Rocketbook and Softbook) or with specialized devices (e. g. 3d glasses and smart shoes).
Electronic game audio devices such as the PSP, Gizmondo, and IPod are very powerful and relatively inexpensive computers. These can be hacked and used for educational purposes, other than educational gaming. At Athabasca University, researchers are facilitating access to library resources using gaming devices and other handhelds [5]. Moreover a whole new generation of mobile devices is now appearing: Full Windows XP PCs are now available as handheld wireless computers (OQO, VaioVGN170, Antelope, FlipStart).  These powerful handhelds open up a whole new world of possibilities for educators.
For delivering content on mobile devices, standard based learning objects (LO) are essential. They support accessibility from a wide variety of mobile devices and PCs using interoperable standards. A LO can be defined as any reusable digital resource that is encapsulated in a lesson or assemblage of lessons grouped in units, modules and even programmes.  A lesson can be defined as a piece of instruction, normally including a learning purpose or purposes. There are other definitions [6] [7, 8], but this is one that is practical and implementable [9]. 

2. Learning objects
A LO can be made from a wide variety of content materials.  They exist and interoperate at different levels of granularity.  A simple knowledge object could be a text document, a photograph, a video clip, a 3D image, a Java applet or any other simple content unit.  For example, a video clip from the recent Hurricane Katrina would be an example of a simple media object.  It becomes more useful for learners when a lesson is added to it.  Many different lessons can be created from one component.  This one video clip could form part of lessons in climatology, religion, politics, history, ethics, media studies, etc.  These mini-lessons are best suited for mobile learners who would be able to access complete units of lessons in brief time periods using their PDAs or mobile phones. Longer learning experiences or groupings of lessons can be built from these smaller units.  Short modules can consist of groups of  five to ten minute lessons as part of larger modules that can then become part of a full semester course.
Learning scenarios for use on small mobile devices should therefore be designed as a collection of LOs rather than as whole, inseparable, long courses.  In order to search for and find these LOs, descriptions of their characteristics are needed. 
For this you need metadata that describes their many features. Metadata is essential for addressing LOs. Metadata is simply the data that describes an LO (cf. the label on a can of soup or library catalogue card). The IEEE Learning Object Medatadata (LOM) standard contains many elements (IEEE LOM 1484.12.1 – 2002). 
Metadata is also essential for the implementation of the semantic web. The semantic web, envisioned by Tim Berners-Lee, and supported by the W3C provides a common framework that allows data to be shared and reused. Using RDF, XML and URIs [10]. 
The semantic web makes the WWW more understandable by computer programs, particularly intelligent software agents, by dealing with hierarchical relationships between meanings, by revealing similarities and differences in meaning and providing logical rules for making inferences.
Presently, the WWW can be syntactically interpreted by software applications, but they are limited in their ability to semantically interpret web pages. It takes a human to extrapolate meaning. As the information on the web grows exponentially, becoming unmanageable by humans, we will have to rely more and more on the ability of these applications or intelligent agents to interpret meaning. For this, the software applications need metadata.
Standards-based pedagogical metadata implementations on mobile devices are conspicuously absent in the literature. There is much written on metadata for contextual awareness [11] [12], Allert et al [13] focus on metadata for learning management systems. But, few papers focus on the pedagogical metadata needed to ensure the interoperability of multimedia learning content using mobile devices [14, 15] [16] . 
3. CanCore
CanCore is an application profile for the LOM that provides guidelines that simplify the implementation of pedagogical metadata using a subset of IEEE LOM elements.  The LOM is becoming the international standard for pedagogical metadata. CanCore is also fully compatible with SCORM, which is becoming essential for training providers wishing to supply the US government and military. CanCore provides information and instruction on how to implement each element in the LOM, including explanations, recommendations on syntax and vocabulary, examples in simple language and XML, as well as technical implementation notes.

   The IEEE LOM Data Model is considered to be too complicated for effective implementation. The IMS Best Practices and Implementation Guide states: "Many vendors [have] expressed little or no interest in developing products that [are] required to support a set of meta-data with over 80 elements" [17]. CanCore accepts that implementers will have a wide variety of needs for metadata and recommends up to 32 fields, making none of them mandatory.  This is about halfway between the Dublin Core (15 fields) and SCORM (c. 72 fields). At the same time, CanCore recommendations are available for all the IEEE LOM fields.
   The international elearning specifications & standards communities are largely concerned with syntax and the technical interoperation. Effective metadata requires semantic specification and consensus often specific to the different groups like the education community. CanCore attempts to incorporate the best practice from library and cultural heritage communities, with those of implementers in elearning. No other initiative has done this across multiple e-learning projects.
The LOM and other standards can be implemented with different vocabularies and varying syntax. But, should they? CanCore has been created with the help of early LOM and SCORM implementers in consultation with a broad cross-section of the elearning community aiming for broad semantic and syntactic interoperability.  CanCore guidelines can also be used for implementations of metadata for the ARIADNE, Dublin Core, D-Spacek the Open Knowledge and Open Archive initiatives.
CanCore recommends the use of a subset of LOM elements based on their value in searching for, retrieving and reusing LOs as well as their use in metadata record-sharing between independent LOM-based LO repositories. CanCore, like the LOM does not recommend mandatory elements. Any number of elements can be present or absent. All elements are optional. Of particular importance to instructional designers, creating mobile learning applications, CanCore (and the LOM) permits the addition of elements outside of the original CanCore subset.
The CanCore recommendations can be used by implementers to save the time and effort required to adapt the LOM themselves, according to all of the conventions and best practices that the LOM itself prescribes. The recommendations remain consistent with the efforts of other first implementers.  CanCore aims to provide the shortest route to optimal interoperability, recommending ways in which these elements can best be added in a consistent format, suggesting adaptations for existing LOM elements to meet specific needs.
The CanCore version 2.0 metadata guidelines are available in French and English in print, PDF and dynamic, searchable Web-based forms [18].  Using the latter format, it is possible to call up CanCore recommendations for the SCORM, SingCore and other metadata subsets [19].  
These guidelines are being used by implementers around the world. See Appendix A in Friesen [20]. More recent adopters include the US-based MERLOT repository, which houses thousands of reusable LOs  in a variety of formats <http://www.merlot.org/Home.po> and the Council of Ministers of Education of Canada (CMEC) learning object portal project.  CanCore is the leading application for resource metadata in Canada and it is becoming widely recognized internationally.  For more information about CanCore, see http://www.cancore.ca
4.  Mobile devices and Cancore
CanCore has been specifically developed and adapted to facilitate the description of rich, bandwidth-intensive multimedia resources, and is particularly appropriate for supporting implementations that are to be accessed using a wide variety of technological and pedagogical environments, including mobile devices. CanCore specifications allow for greater reuse and portability of resources, systems and content of many kinds across applications and operating systems. Educators implementing mobile learning environments can take advantage of a wide variety of international standards-based resources already available online in learning object repositories (See for example: [21] [22] [23]
If mobile learning is to be "all the time everywhere” then the LOs used must be interoperable and adaptable for use at different times and in different contexts using a variety of devices in a range of formats.  Capra [24] propose a distinction between active and passive  metadata for mobile systems: passive information, enabling an application to react to changes in the context; and active information, which delimits the context and the action required. Kawarasaki et al. [25] propose metadata describing terminal capabilities; Specht and Kravcik [26] experiment with the automatic acquisition of context metadata Yang et al. [12] developed a personalized metadata mechanism for a mobile learning environment without addressing metadata problems. 
Friesen [27] addressed the specifics of specialized metadata for mobile devices proposing that key elements in mobile learning are indicators specifically of context and situation and these must be expressed as metadata including time and geographic location.  Naito [28] proposed the W3C's NaVigation Markup Language (NVML) for spatial information using latitude and longitude, and the 24-hour clock for indication of time.  
The LOM, while disallowing replacements of existing data elements, does allow for extensibility.  The LOM data elements and data model represent a "base schema" allowing for extensions as "taxons".  Friesen and McGreal [22] proposed using NVML for location and the ISO 8601 standard, for time where it is expressed as YYYY-MM-DD hh:mm:ss.  A GPS-enabled wireless device could then be used to determine specific actions based on the geographical and time data supplied.
5. Conclusion
From the learners’ perspective, metadata should be invisible, while enabling intelligent software agents to discover and make available the right learning modules (LOs) at the right time and in the right context. Mobile learning is in its infancy. If it is to move forward, educational content developers must build LOs using international standard metadata. Pedagogical and other types of metadata are essential in the implementation of learning systems for use by mobile devices. Metadata is key to the use of learning objects. Learning objects represent a means of rendering learning content interoperable on a wide range of devices in different formats using XML for usability on small and large screens. To ensure discoverability and repository interoperability, using intelligent agents, metadata is indispensable. 
CanCore is an internationally recognized  metadata profile for implementing the IEEE LOM, thus advancing the use of learning objects. With enhancements to the profile and to the LOM, providing for location and time, as well as other contextual information, mobile devices can be used effectively as an extension of the global data infrastructure.
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