Learning as a Service: A Web-Based Learning ... - Springer Link

Learning as a Service: A Web-Based Learning Framework for Communities of Professionals on the Web 2.0 Marc Spaniol, Ralf Klamma, and Yiwei Cao RWTH Aachen University, Informatik 5, Ahornstr. 55, D-52056 Aachen, Germany {mspaniol,klamma,cao}@cs.rwth-aachen.de

Abstract. With the advent of the Web 2.0 technologies, web-based learning is shifting to new learning community driven requirements. While the success of web-based learning (still) requires a careful selection of appropriate communication/collaboration tools, the underlying software methodology is shifting from (passive) content consumption towards (active) content creation. Even more, the professionals’ sociocultural background influences the attitude towards the collaberatively created learning contents. Thus, successful web-based learning community hosting for professionals depends on a comprehensive cross-media support such as capabilities to share drawings, animations, pictures, digital videos, texts etc. among users. In this paper, we present the “Learning As a Service” (LAS ) framework. LAS is an approach supporting webbased learning for professionals on the Web 2.0. It employs advanced multimedia technologies in order to promote a wide range of web-based learning community information systems for interdisciplinary, intercultural as well as intergenerational learning. We present a set of services on the basis of LAS showing best practices for various application scenarios. Keywords: Technology Enhanced Learning, Web 2.0, Multimedia, Metadata, Web Services, SOA.

1

Introduction

Providing learners with the most suitable contents at any time and in any context is one of the most critical aspects in technology enhanced learning. In particular, the design of web-based learning applications for communities of professionals is a challenging issue. This problem becomes even more visible when the applications aim at supporting interdisciplinary, intercultural, and intergenerational learning communities. Furthermore, problems arise if the heterogeneous needs of professionals have to be satisfied. While “classical” E-Learning systems try to overcome these problems by applying learner modeling strategies like IMS Learning Design in order to select and customize the content delivery within a single application, “Learning As a Service” (LAS ) aims at the flexible orchestration of social software within a web-based learning framework according to the professionals’ needs. H. Leung et al. (Eds.): ICWL 2007, LNCS 4823, pp. 160–173, 2008. c Springer-Verlag Berlin Heidelberg 2008 

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In addition, multimedia technologies, social software and new Web 2.0 business models are rapidly developing and giving rise to new hardware and software requirements. Combined with a trend for multidisciplinary work and research, novel approaches for flexible, evolving, adaptable, and interoperable community engines are required. The success of social software and Web 2.0 depends greatly on user-generated content, since one of the Web 2.0 business models is “Data is the next Intel Inside”. But available social software solutions often neglect requirements of user communities. Therefore, social software and Web 2.0 need to reflect the nature of the underlying community processes and their discourses for technology enhanced learning. Consequently, the first research question is how to exploit the features of the Web 2.0 in order to design flexible, constructable web-based learning frameworks? The design of applications for web-based learning for interdisciplinary professional communities of practice (in general) and for web-based learning frameworks (in particular) is a challenging issue [23,27,35]. Principles like legitimate peripheral participation, group knowledge, situated learning, informality, and co-location have to be taken seriously during the design of the learning framework. For that reason, the web-based learning framework has to reflect the social learning processes which are very community-specific. Even more, (some) non-technical communities of professionals are usually not able to express their needs in the very beginning of technology enhanced learning application usage. Thus, the communities have to gain experiences on their own learning processes while using the systems. Additionally, the multimedia technologies are being developed so rapidly that great hardware and network capabilities are required. Consequently, the second research question is how to bring system developers and user communities together in order to jointly develop technology enhanced learning solutions? In this paper we present a novel approach to realization of freely constructible web-based learning applications in the Web 2.0 era based on our “Learning As a Service” (LAS ) framework. In order to meet these requirements we combine approaches from various disciplines such as software engineering, sociology and cultural sciences, led by the transcriptivity idea as a design principle in computer science [17,19]. The development process of community information systems is based on ideas of joining usability and sociability [29] by constantly assessing and supporting community needs in a socio-technical information system development process. From the technical point of view, the server architecture of the LAS framework allows communities to add, remove and exchange services in their community information system from anywhere at runtime. On top of it, we design and implement a Web 2.0 community platform, the Virtual Campfire, a technology enhanced learning environment for communities of professionals e.g. in cultural heritage management. The rest of the paper is organized as follows. In Section 2 we give an overview of recent trends on the Web 2.0 with a focus on courseware management systems. Particularly, we discuss how far web-based learning specific courseware management systems are capable of community support in a Web 2.0 fashion. We will

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point out, that the desired solution requires bridging the gap between (passive) content consumption in the Web 1.0 and (active) content creation in the Web 2.0. In Section 3 we introduce LAS as a framework to comply with these tasks. Even more, we explain its technical features for the modular composition of services. After that, we present Virtual Campfire and its core modules in a scenario of non-linear multimedia storytelling for professionals in the application area of cultural heritage management in Section 4. The paper closes with a summary and an outlook on further research.

2

Recent Trends on the Web 2.0 - CMS Reviewed

In a rapidly changing world of Web applications, web-based learning has got in place recently. Nowadays, the Web 1.0 is shaken by the fundamental changes brought by the emergence of a new understanding of the Web itself. The term “Web 2.0” is therewith coined. In the Web 2.0 era the attitude towards software has changed dramatically. Projects like Wikipedia create knowledge prosumers, which unify consumers and producers, and participation becomes essential for wikis. They are replacing those now old-fashioned content management systems in organizations. Interoperability between content and services is realized by syndications tools such as the RSS. In a similar fashion, this also holds for courseware management systems. In order to highlight these differences between the “new” and the “old” Web paradigms, we introduce the core Web 2.0 business processes presented in O’Reilly’s seminal article [28]. We will not repeat all features of the Web 2.0 here, but put forward the impact of Web 2.0 technologies on web-based learning. In addition, we discuss whether and how far the most prominent courseware management systems (CMS) such as Blackboard Academic SuiteTM [8], CLIX [15] or Moodle [25] “comply” with the Web 2.0 concepts. 2.1

Folksonomies

Tags are user-generated keywords (metadata) describing content (data). Web 2.0 uses tagging technologies for the categorization of multimedia content, usable for search and retrieval of very large collections. So far, the use of contentbased retrieval techniques was limited for multimedia content, since they only work efficiently enough on a limited amount of material. Even more, in some larger collections, only a limited amount of retrieved multimedia content has a high ratio in terms of precision and recall. However, a “semantic gap” between the technical extraction of metadata and the semantically correct interpretation of content can be recognized [6]. In this aspect, tagging systems have the shortcoming that they only offer plain keywords, where tags carry their semantics implicitly only. Despite their potential in improving search and retrieval of multimedia contents, tagging systems face the problem inherent in the implicit semantics of the vocabulary used for tagging [7,24]. Particularly, the semantics are not accessible for further machine processing. Current trends and evolving standards in multimedia technologies are intended for enriching multimedia content with semantic metadata leading to more advanced multimedia management

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and retrieval methods in order to handle the dramatically increasing amount of publicly available multimedia content on the web [5]. Consequently, the tags themselves should carry their semantics explicitly in order to make this additional information machine-accessible. For web-based technology enhanced learning applications, multimedia and Web 2.0 technologies have to converge on multimedia management. Tagging technologies are needed to retrieve interesting multimedia content, but we also need some kind of emergent semantics for multimedia using well-established contentbased retrieval techniques. In “classical” CMS the concept of folksonomies is unknown. In contrast to the bottom up approach of folksonomies, they mostly stick to a predefined categorization scheme. Nevertheless, CMS like Blackboard Academic SuiteTM , CLIX or Moodle provide other means to access the contents. While Web 2.0 software allows the exploration of all kinds of multimedia, CMS currently only cover learning contents. In the future there will be a clear need to cross-walk between multimedia description standards like Dublin Core [2,12] and MPEG-7 [16,21] on the one hand and Learning Objects Metadata (LOM) [14], SCORM [1] and IMS LD [22] on the other hand. 2.2

Syndication

Lately, Web 2.0 is also featured as a kind of attitude with which people handle interactions on the web. More and more web sites support services like RSS, social bookmarking, and Web site personalization instead of placing a button labeled with “Set this page as your home page”. It has become natural and a kind of fashion to integrate third-party web services like Google, Yahoo and del.icio.us etc. Web services and syndication will be even more important in ubiquitous learning contexts when learners need support based on their location, their schedule, their connectivity, their device capabilities and their usage context. Content has to be adapted to the various unreliable or hardly predictable contexts of the learners instead of delivering the same content to every learner in every situation. Syndication is somewhat a “new” concept to CMS. However, CMS focus on interoperability of learning contents. While systems like Blackboard Academic SuiteTM , CLIX or Moodle “syndicate” their contents in interoperable metadata standards, they have not yet discovered the multimedia description standards or even other standards from entertainment, library sciences, science and so on. Nevertheless, with the advent of Web Services Blackboard Academic SuiteTM , CLIX or Moodle have got more and more openness and become “service-oriented”. 2.3

Participation

“Everybody’s invited!” is the slogan of social software ranging from the social bookmarking pioneer del.icio.us to Wikipedia. Users can subscribe to communities in order to make their contributions to a dedicated topic regardless of social background, age or ethnicity. Thus, social networks are facilitated up to

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get a broader perspective on available information (opinion network) instead of a narrowed-by-personalization piece of information. In the present information world, one can get whatever information he wants by finding the right community. Social navigation, social recommendation and social filtering techniques are even more important in a multimedia Web, while classical information retrieval techniques only provide limited support for communities’ participation. For example, merging and recombination of content is a technique which can be easily applied on existing Web 2.0 multimedia repositories. Nevertheless, participation sets new challenges for content retrieval techniques. It is questionable, what information quality can be retrieved from Wikipedia (cf. http://en.wikipedia.org) and Wikimedia Commons (cf. http://commons.wikimedia.org) e.g. related to the two different architectural styles of Florence Duomo’s cathedral. Referred to “classical” CMS, Blackboard Academic SuiteTM , CLIX or Moodle are based on participation, too. However, participation of contents is usually based on a learner model and sophisticated roles. While Moodle is the pioneer in being more or less the “Wikipedia” of E-Learning, also Blackboard Academic SuiteTM and CLIX have just discovered the power of bottom up activities. Thus, the trend in CMS goes to collaborative authoring by shifting from consumption to prosumption. Thus, wikis are providing an approach to contextualization of learning content as much as possible. However, the wiki approach is different as it tells the story behind the content. 2.4

Sharing Knowledge and Control

Control freaks are worrying about the principal openness of the new social software applications like diverse wikis, but it turnes out that participation increases just by those low barriers. Even if inappropriate content is uploaded or created, or existing content is modified or even vandalized, the communities have some self-repair strategies and developing social norms in place which are more flexible than any technological approach protecting content. But when these repair strategies do not work anymore, the community may have problems by itself and will disappear eventually. This openness accepts various types of multimedia. It is possible to reuse multimedia, which takes advantage of well-rated community media. Rip, mix, and burn as classical multimedia sharing models have to be re-invented for learning communities. While it is relatively easy to forward a YouTube video, it is still a professional task to edit new videos out of existing materials for learning purposes, which is not yet well supported by either social software or CMS. Digital media allows fast creation, sharing and consumption of interactive content. “Classical” CMS like Blackboard Academic SuiteTM , CLIX or Moodle aim at delivering learning objects. Their contents are “valid only” in certain conditions such as a particular status of the learner model. To the best of our knowledge there is no way in the moment to allow learning designers or learners to create, share or consume re-contextualized multimedia contents in a Web 2.0 manner.

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165

Summary

There is a gap between (passive) content consumption in “classical” CMS and (active) content creation in Web 2.0. However, the gap is not such big as it might appear at first sight. It can be recognized that there is an increasing alignment of CMS like Blackboard Academic SuiteTM , CLIX or Moodle move towards the Web Services and Web 2.0 (c.f. Table 1). In this aspect, particularly CLIX has introduced sophisticated features towards Web 2.0 functionalities in its recent version. Table 1. Differences between Technologies for CMS and Social Software Web 2.0 Paradigm

Technologies in Social Software

Technologies in CMS

Folksonomies

Tagging

Categorization

Syndication

Web-Services, RSS, MPEG-7

SCORM, SOA

Participation

Community

Based on Learner Models

Knowledge Sharing

Multimedia, Stories

Learning Objects

Correspondingly, we’ll present an approach that might help developers as well as learning communities narrow or even close the gap between “classical” courseware management systems and freely adjustable Web 2.0 technologies. The “Learning As a Service” (LAS ) Framework uses Web 2.0 technologies and provides services for: • Exploration of multimedia contents (Folksonomies & Participation) • Collaborative authoring of multimedia contents (Syndication & Participation) • Re-contextualization of episodic knowledge (Knowledge Sharing & Participation)

3

The “Learning as a Service” Framework - LAS

With both aforementioned research questions, our research starts from media theoretical starting point. Empirical studies have shown that there are considerable differences in the perception process of learners depending on the medium through which the content has been communicated [11,13]. Even more, dedicated studies on the efficiency of computer mediated communication indicate that not a single medium might be considered most suitable, but an almost freely configurable media mix is the solution of choice [26,30]. That means a singular artifact lacks its context. Thus, it is impossible to create knowledge separately from the media through which it is communicated. Similarly, media play a crucial role

M. Spaniol, R. Klamma, and Y. Cao

…

LAS Services

SOAP

…

HTTP

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Fig. 1. Simplified LAS Architecture

in technology enhanced learning. Especially, multimedia processing features are required within the community’s collaboration platform because of the variety of end user devices, network capabilities, and other factors in the learning context. In order to encourage and enable communities to decide about the features and adjust the functionalities of their learning community information systems, a constant self-monitoring and self-reflection process is required. Correspondingly, the orchestration of services within the web-based learning framework is part of the professional communities’ learning process itself. In addition, the interoperability of multimedia contents is an indispensable prerequisite. For that purpose, “Learning As a Service” (LAS ) is a framework to simplify the development of web-based applications in order to support technology enhanced learning for professionals. It offers an open architecture that helps professionals to create community information systems in versatile application domains. It employs advanced multimedia standards and database technologies that support the realization of the state-of-the-art community information systems for web-based technology enhanced learning. As a result, LAS bridges the gap between classical web-based learning specific courseware management systems and freely adjustable but not web-based learning specific community engines. In addition, advanced multimedia technologies are employed to support a wide range of communities for interdisciplinary, intercultural and intergenerational learning. The highlights are the incorporation of multimedia content adaptation to the learning communities and a framework of learning services that help professionals create information systems in order to foster knowledge sharing in communities. Its architecture is based on a lightweight application server as a community engine that supports various services such as user management services, MPEG-7 services, database connection services etc. (cf. [20] for details). In technical details, LAS is a platform-independent lightweight middleware platform implemented in Java. It employs principles of service oriented architectures (SOA) to provide web-based learning services. The learning services can be

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shared among various tools to support the work of professionals in communities of practice. The LAS API and its concepts are used to build the server’s functionality and thus allow open and user-defined server extensions by three basic element types: connectors, components and services. Figure 1 shows a simplified diagram of the LAS architecture and the interrelations among server elements (cf. [32] for details). What makes the “Learning as a Service” Framework LAS unique is its capability of hosting a large number of overlapping web-based learning communities at once. Agents grant a variety of rights for different learning communities. Furthermore, the architecture of the server software is able to run either a heavyweight XML based community engine or a very thin and hardware saving offline server on mobile devices for later synchronization in the ongoing development. The main task of LAS is to maintain the clean and orderly service oriented architecture by keeping all learning infrastructure logic on the server side. The main focus of LAS is rather server-side development than front-end user interface or related functionality like JSP containers, Servlet engines or HTML templates. Through a performance evaluation, LAS is much easier to use and configure than application servers like Tomcat [3], other J2EE application servers [18] or ZOPE/PLONE [36,37] to support web-based solutions. The main difference to such frameworks is that LAS tries to offer service programmers as much flexibility as possible. Developers are supported to concentrate on the middleware level of the overall architecture through a very flexible and fine grained user, group and rights management. In addition, a LAS environment allows hot deployment, i.e. dynamic reloading of services and components at runtime.

4

Virtual Campfire: Learning as a Service Applied

In this section, we demonstrate a web-based learning approach based on the LAS framework, so-called Virtual Campfire. The starting point is to use storytelling for technology enhanced learning in user communities who share knowledge about cultural heritage management. While corporate learning has been incorporating storytelling approaches for many years [9], the general technology enhanced learning is not advanced in using stories very much for educational purposes on the web. To explore the potentials of social software, Virtual Campfire employs a set of community tools including Semantic Zapping Services, Collaboration Services and Storytelling Services all based on LAS to inspire communities for storytelling and cultural knowledge sharing. 4.1

Semantic Zapping Services: Metadata Standard Driven Exploration of Multimedia Contents

Semantic Zapping Services in Virtual Campfire try to bridge the gap between folksonomy-style high-level semantic knowledge about multimedia and purely technical low-level content descriptions. These services are intended to support collaboration in communities by the exchange of multimedia contents and their

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low-level and high-level semantic descriptions. In order to ensure interoperability among the contents description multimedia metadata standards are being incorporated. In this aspect, the Dublin Core (DC) metadata standard [2,12] has its advantages, since it is an easy to understand and a concise method for media annotations in many domains. Nevertheless, DC still has the limitations e.g. not suitable for temporal and media specific annotations of multimedia contents. For that reason, we try to surmount these limitations by combining the loose classifications in DC with more sophisticated description elements for time based media in MPEG-7. Thus, our semantic zapping services are based on an excerpt of the extensive MPEG-7 multimedia metadata standard. Even more, we provide services for a semi-automatic conversion from DC to MPEG-7 [34] while an affiliated FTP server is used for an automated upload and download of multimedia artifacts by the community to the common repository. Consequently, the semantic zapping services of Virtual Campfire allow the community members to search and browse multimedia contents described by MPEG-7 for professional learning purposes. 4.2

Collaboration Services: Collaborative Authoring of Multimedia Contents

Knowledge sharing in Virtual Campfire is supported by annotating, tagging and sharing multimedia contents within the learning community. In contrast to a conventional categorization system, multiple concepts are used for one piece of information. All metadata generated in Virtual Campfire is MPEG-7 compliant by using MPEG-7 LAS service methods. For that purpose, Virtual Campfire offers two types of tagging: keyword tagging and semantic tagging (cf. Figure 2). Keyword tagging enables users to assign a set of plain keywords to an image, as it can be done in Flickr (cf. www.flickr.com). However, one prominent problem of plain keyword tagging is the potential risk of semantic ambiguities. For example, consider the word “Portrait” being a polysemy of different meanings: A certain kind of painting or a dedicated camera angle. While plain keyword tagging users would assign the identical keyword tag to both media, semantic tagging reflects this difference in semantic meanings by assigning two different semantic tags. Therefore, semantic tagging goes a step further by allowing the users to define semantic entities and to assign semantic entity references to an image or a video. Different from plain keyword tags that are represented by their name exclusively, semantic tags consist of a name, an optional definition, a mandatory type and optional type specific information. Following the MPEG-7 standard, semantic tags are classified into the seven semantic tag types Agent, Object, Place, Time, Event, Concept and State. Each of these seven types allows the specification of additional type-specific information of learning contents such as geographic coordinates for locations, time stamps resp. intervals for time, parameter name/value pairs for states, etc. For example, one could not derive from a plaintext keyword Buddha, that it describes an agent, while for semantic tagging, Buddha has been modeled as a semantic entity of type agent. Semantic entities are defined based on the methods provided by the

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Fig. 2. Keyword and Semantic Tagging of Multimedia Contents

SemanticBasetypeService. Semantic references are assigned to images using methods of MultimediaContentService. All these high-level content descriptions can be cross-walked with any learning standard by fixed mappings or even dynamically by mapping services [10]. Similarly, retrieval is based on the multimedia descriptions. For multimedia retrieval by plain keyword tags users can formulate keyword search expressions in propositional logic formulae using keywords as atomic propositions. For example, the keyword search expression “Buddha ∧ Bamiyan ∧ ¬(Destroyed ∨ Taliban)” would retrieve all images and videos having been assigned with the keywords Buddha and Bamiyan, but none of the two keywords Destroyed or Taliban. The concepts above are transferable to the more expressive semantic tagging, which can be easily realized on the basis of the MPEG-7 services. 4.3

Storytelling Services: Re-contextualization of Episodic Knowledge

Re-contextualization of episodic knowledge Virtual Campfire provides dedicated non-linear storytelling services. In order to help learning designers or learners at creating useful stories (from a structural point of view), the MOD paradigm [31] is being applied as a theoretical basis. For the sake of brevity, we only briefly discuss the major principles of this service. A detailed description can be found in [33].

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Fig. 3. A non-linear Story created in the MIST [33] Service of Virtual Campfire

Two dedicated user interfaces are available for the storytelling services, an editor and a player. The editor allows users to edit already existing non-linear multimedia stories or to create a new one. The player is used to consume and interact with existing non-linear multimedia stories. Besides the explicit knowledge contained in the multimedia contents the high-level semantic tags are also accessible here. These contents can be thereafter temporally arranged in the way that they depend on a certain context. At creating a story authors can create paths covering different problematic aspects along the contents. Thus, the problems addressed depend on the path selected and lead consequently to different results in a story. Figure 3 shows the editor consisting of three main elements: storyboard (left-hand side), plot (upper right-hand side), and semantic annotations (lower right-hand side). The plot in upper right panel represents the declarative knowledge captured in a story. It is rendered by a tree hierarchy which allows the further decomposition into sub-problems. In addition, problems addressed in a multimedia story can be linked to related multimedia contents. The storyboard in the left panel illustrates a visualization of episodic knowledge as paths between content elements. In addition, the decomposition of stories according to MOD paradigm into begin (B), middle (M), and end (E) is depicted. Finally, in the lower right panel additional semantic annotations can be added to any multimedia element. Thus, users may express verbal-knowledge being associated with non-verbal knowledge.

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Conclusions and Outlook

The rapid growth of Social Software and Web 2.0 has raised new challenges to design and develop web-based learning applications. Starting from a survey of the employment of Web 2.0 technologies in the courseware management systems, we have presented LAS as a framework for web-based learning services in professional learning communities. As creation of new knowledge in learning processes is a discursive and multistage process, the user requirements are rapidly changing and several new features need to be integrated into web-based learning environments. In contrast to existing implementations the methodology and architecture Virtual Campfire is more flexible to assess the community needs over time and to integrate the community members in the community development process. Even more, the semantic zapping services of Virtual Campfire based on MPEG-7 provide interoperability and exchangeability of learning contents. Thus, LAS simplifies the support process for communities of practice drastically and offers at the same time much more flexibility in the development process. Based on the LAS framework we can now easily create and deploy MPEG-7 services. With the power of the MPEG-7 services realized on top of the unique community engine LAS we can create web-based learning environments like Virtual Campfire in a systematic way. A possibly thin client is the main advantage of our approach against the-state-of-art frameworks such as AJAX [5]. With the growing importance of mobile and ubiquitous applications the server still should handle the computational complexity while clients may be able to reduce computational load with limited computational power. We will also develop a mobile Virtual Campfire demonstrator for the LAS framework, based on the different connectors available. In our ongoing research work we are going to investigate unsupervised learning algorithms to unleash fully the power combining low-level and high-level semantics of multimedia materials in social software applications. LAS simplifies the learning community support process. However, the direct support of computer programmers and learning designers is still needed. In future, graphical editing support for community web sites could leave even more development responsibilities to communities.

Acknowledgements This work was supported by German National Science Foundation (DFG) within the collaborative research centers SFB/FK 427 “Media and Cultural Communication”, within the research cluster established under the excellence initiative of the German government “Ultra High-Speed Mobile Information and Communication (UMIC)” and by the 6th Framework IST programme of the EC through the Network of Excellence in Professional Learning (PROLEARN) IST-2003507310. We thank our colleagues Nalin Sharda and Georgios Toubekis for the inspiring discussions. In addition, we thank our students D. Renzel, H. Janßen, M. Pienkos, P. M. Cuong, D. Andrikopoulos and A. Hahne for the implementation of the Virtual Campfire services.

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