Vigils in a Wilderness of Knowledge: Metadata in Learning Environments

Ralf Klamma, Elisabeth Hollender, Matthias Jarke, Petra Moog, Volker Wulf Lehrstuhl für Informatik V, RWTH Aachen Ahornstr. 55, D-52056 Aachen, Germany

E-mail: klamma@cs.rwth-aachen.de

Abstract

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The paper presents two computer-supported learning

environments which are built on top metadata defined in XML; a comprehensive study environment for a Talmudic tractate and a video based learning environment called Virtual Entrepreneurship lab used in entrepreneurship education. While expressive metadata standards like MPEG-7 help us technically to implement multimedia learning environments by offering comprehensive coverage of all needed aspects, the century spanning editing process of knowledge encyclopaedias like the Babylonian Talmud offers useful hints what kind of metadata are necessary to disclose the knowledge structures in non-linear material. 1. Introduction

Many approaches to learning environments have been proposed in the last years [1, 9, 11, 17, 18]. Still, the use of metadata and especially metadata standards is still evolving. There are some proposals for learning data standards and projects using metadata. [2, 3, 4, 5, 6, 13, 14, 21, 22] especially for technical and organizational aspects. There are different meta data initiatives to come to an unified naming of data worldwide, e.g. Dublin Core [5, 10], which is the basis for further developments of metadata standards, Resource Description Framework RDF [24] for the management of metadata on the world wide web and the MPEG-7 format [15, 20], which covers many approaches for describing multimedia metadata.

The knowledge structures in the given material students have to disclose to learn successfully is reflected more seldom .

In this paper we present and discuss two prototypes of learning environments we developed in two interdisciplinary projects. The comprehensive electronic study environment (CESE) [12] is a learning environment for Talmudic tractates developed together with researcher from Jewish studies. The Virtual Entrepreneurship lab [16] is a video-based learning environment based on MPEG-7 metadata standard developed to strengthen

entrepreneurship education. After presenting some key features of our

environments we discuss the use of metadata for unveiling knowledge structures inscribed in the material. The paper concludes with a summary and an outlook. 2. Virtual Entrepreneurship Lab (VEL)

Concepts for teaching of future entrepreneurs differ extremely from country to country and from university to university. There are for example the classical business planning games which simplify situations that occur in the reality but guarantee standards in education. These concepts are replaced or completed more and more by more realistic forms of education. Hypermedia learning environments amalgamate the concepts of working with hypertext and the consequent use of multimedia material. The learning environment “Berliner sehen” developed by Kurt Fendt and Ellen Crocker at the MIT Germany program [7] supports students in learning German language and culture. The basic principle of “Berliner sehen” are video taped talks with different actors living in a specific quarter of Berlin . The student explore the material by choosing a character and a category in the user interface. The multimedia material (digital video, images, and text) is presented according to the selection of the student. The student can play individual talks and browsing them by implicit or explicit links. The student can also change the context of the actual document and gets a new selection of linked documents presenting the new context. Viewing the material and changing perspectives can lead to a different understanding of the material. This is non-linear and flexible. The explorative way of researching the material, the repeated viewing of documents in different contexts, the comparison of results with other students, and the discussion with teachers and other students leads to the learning effects wished by constructivist theory.

The Virtual Entrepreneurship Lab (VEL) works with the basic principles of “Berliner sehen” to support the entrepreneurship education. The learning environment was a joint development from computer science (RWTH Aachen, Fraunhofer FIT) and management science

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(Institut für Mittelstandsforschung, Bonn). Multimedia learning objects are used to create comprehensive context-oriented learning scenarios. This includes interviews with entrepreneurs, venture capitalists, business angels and other persons who have been involved in the process of founding a company. The video sequences are supplemented with other multimedia objects like pictures and text.

The learner takes the role of a researcher, who at first faces an unstructured accumulation of the material. All media that are integrated into the learning environment are assigned to several contexts, which represent certain views on the material. These contexts are described as metadata both visible in the user interface (right sided buttons in Figure 1) and in the material. While working with the VEL the learner can dynamically change these contexts and after that gets presented all assigned media, which can be viewed and analyzed. Main aspect of the design and implementation process of the VEL was the openness of the system. The term “open learning environment” means, that it can be adapted to other areas than the entrepreneurship education and that the learning material can easily be extended and administrated in modules. To guarantee this openness all metadata for the different media has to be represented in an open and flexible manner. Therefore the MPEG-7 metadata standard [15] was chosen for storing all necessary information of the different media. MPEG-7 is a base for applications, in order to enable qualitative access to the content of multimedia data. One the one hand this is filtering, searching and retrieval of information, on the other hand it is linking and arranging of media and personalized access to the data. MPEG-7 has the biggest set of descriptors for audio-visual material at all [15]. If you decide to use MPEG-7 in applications, it is not necessary to know the whole standard, as you can use different levels of granularity for the description of the media.

Figure 1: Screenshot of the VEL (all readable information in German).

Another functionality of the VEL is the learners possibility to create own multimedia collections (bottom of Figure 1). With this collections he can store own perspectives of the material, own trails through the media and own textual annotations [8]. He can mark the collections private or public. Public collections can be seen by all users of the VEL. All these metadata (information about the user, the media, annotations, etc.) are also stored in the database as MPEG-7 XML documents. This is another indication for the expressiveness of MPEG-7: You can describe personalized multimedia collections of different media.

The usage of the MEPG-7 metadata standard to describe all information necessary to arrange and present media, to navigate in the VEL and to create own collections and annotations is the main reason to realize openness, flexibility and adaptability in the VEL. You can easily administrate and extend the learning material by editing, adding and deleting the related MPEG-7 documents. If you are familiar with MPEG-7 you will understand the syntax and semantic of the VEL MPEG-7 documents at once. Furthermore it is possible to exchange data between applications that “understand” MPEG-7. MPEG-7 is XML-based [23]. The syntax and semantic

of correct MPEG-7 documents are defined by a XML schema [23]. For the VEL a subset of the whole MPEG-7 standard was chosen to define all elements that are necessary to guarantee the correct functionality of the learning environment. This include common information about the metadata, copyright information, information about the media type, link to the media, information about the creation process, semantic information to generate the contexts and some video specific information. This subset is defined in a Document Type Definition (DTD). To check the correctness of VEL MPEG-7 documents it is possible to validate them against the MPEG-7 schema and the defined DTD.

3. Comprehensive Study Environment for a Talmudic tractate (CESE)

In the collaborative research center SFB/FK 427 “Media and cultural communication”, a joint research effort of the universities of Aachen, Bonn and Cologne in Germany, we developed a comprehensive environment for studying a Talmudic Tractate. The Babylonian Talmud is the largest collection of texts from rabbinic literature, covering some 5000 folio pages in the standard edition printed by Romm in Vilna (1880-1886). It is also one of the favorite examples of existing hypertexts before hypertext theory. Its traditional layout with the Mishna

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and the Gemara as the main block on the page and several commentaries grouped around them, first developed by the Christian printer Daniel Bomberg in Venice (1520-23), has invited many interpretations both from scholars of Jewish Studies and from hypertext-specialists and scholars of literary hypertexts [19]. It might be worthwhile to analyze this before discussing the possible creating of a “hypermedia-Talmud”. The hypertext metaphor can be doubly applied to the Talmud: Both the external structure of the Talmud and its internal structure can be described as hypertext.

Figure 2: Screenshot of the study environment in an internet browser (all readable information in Figure

German and Hebrew).

The external structure is the combination of texts on the traditional page of Talmud. The main texts on the page are the Mishna, edited in the 2nd century C.E., and the Gemara, that was probably closed in the 8th to 9th century C.E. They are carefully edited compilations that show the traces of several editing processes, each of them with its own agenda for the logical, rhetorical and thematic outline of the texts. The medieval and early modern commentaries included in the printed editions were composed by single authors (with the exception of the Tosafot, whose publishing-history differs from that of all other commentaries) either as commentaries on the completed and closed texts of the Babylonian Talmud or on single tractates, or as supercommentaries on preexisting commentaries. All commentaries take up lemmata from the talmudic text and create links into the text, attaching their own explanations. While we read and study the talmudic page by looking for links from the inside to the outside, the commentators actually created links from the “outside” to the “inside”. Most of the older commentaries were not originally written on the margins of copies of the Talmud. They required the use of two manuscripts simultaneously. The page of Talmud therefore fits the description of hypertext: it brings

together and links documents in a way that enables the reader to use several connected documents at the same time.

As to the internal structure of the talmudic text, it can be also described as a hypertext because, like all rabbinic texts, it is a unique combination of new and old material. In each text we find a great number of passages that occur in parallel transmissions of textual units copied from their sources and inserted at suitable positions in the target texts. This created an internal hypertext-structure that connected Midrashim and Talmudim via nodes of shared text. Associations and structures were created that connected the different parts of the Talmud and enabled different ways of reading. The Gemara itself is – beyond the linear text – a web of units connected by associations that offer a multitude of possible readings. In spite of this it should be noted that the talmudic text is not fragmented in the way modern hypertexts are usually structured. Every electronic presentation of the Talmud will have to address a specific audience with its specific needs.

None of the available hypertext packages support all the initial requirements, such as Hebrew language and hypermedial representation and the hypertextual presentation of the documents. Hence, we need a representation and presentation language which is capable of fulfilling the requirements mentioned. Fortunately, the set of presentation and representation languages grouped around the XML technology solve our problem. To transform the document space given by MS Word documents we chose XML for the following reasons. First, XML allows hypertext linking features. Second, XML provides extensive hypermedia linking facilities with extensions like XLink and Xpointer. Third, XML is specified for Unicode use, thus supporting also Hebrew. Fourth, there are available XML databases to construct a database. To summarize, XML technology was an ideal candidate for designing and implementing the study environment. To realize a XML-based study environment we need a DTD consisting all necessary metadata for two main reasons. First, we want to realize a database containing hypermedia objects semantically tagged by XML. Hence, for describing schema information a DTD is a good choice. Second, we want to semi-automatically transform existing materials, such as German translations of Mishna, Tosefta and Babylonian Talmud Megilla into XML documents to fill our database. For every given XML document we can check well-formedness according to the definition of XML, e.g. that every position of opening and closing tags is correct, and validate against a given DTD. After performing these two procedures we can ensure that the XML document can be represented on the screen with XSL. We developed a XSL stylesheet for representing the XML documents as HTML pages using JavaScript as script language. Since we rely on HTML

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The Babylonian Talmud is besides its role as source of religious authority an encyclopedia of knowledge of any kind. This knowledge is stored mostly as dialogs, in part logical, in part associative. This offers the opportunity to define different level of reading and learning concepts and to read the text in a non-linear way. This is also shown by many middle age and early modern commentaries of the Talmud which are grouped around the printed page of the Talmud. On the other side, Talmud is still learned cooperatively in Talmud schools (Jeshiwot). Thus, the organization of knowledge in the Talmud is influencing the way, the Talmud is taught. Aim of the CESE is to represent and present the synchronous and historical multidimensionality of the text and the commentaries in an XML based study environment and to offer electronic ways to reconstruct the learning situations in Talmudic schools where the teachers are the mentors of the learning groups, wandering around to listen to the pupils and help them in ongoing discussion.

any popular browser is capable of representing our study environment.

The main feature of the environment is the handling of the multidimensionality of the text. In the environment we can fix certain metadata specified features like the highlighting of bible cites while we can change other features like the language. In Figure 2 the colored sections are these enabled features in the Hebrew language representation of the Talmudic tractate. We can switch to German without loosing our study context. All colored sections remain the same. The loaded document carefully conserves the layout of the printed text. Indentation is kept. The curly brackets in the printed text that marked passages that have parallels in other rabbinic texts were substituted with bright red arrows in the electronic text. Footnotes from the printed translation indicating the exact parallels had to be translated into a different visualization scheme. In this case we chose commentary-boxes that appear when the mouse is moved onto the arrow. The commentaries, many of which are not part of the printed translation, are indicated by blue bullets. Additionally, as in the printed edition, the mishnaic and biblical texts under discussion in the Talmudic text are marked on the left margin of the text. The same column contains indicators for the textual structure.

In our CESE environment we use DTD developed for our special needs since the metadata standards evolved in this long lasting process are sufficient to rebuild the complex, multidimensional Talmud text and commentary electronically. The transcription of the Talmudic tractates will radically change the knowledge community. For now, studying the Talmud in depth is a painful and long lasting process both for religious Jews and students from the Jewish studies. By making the dialogic knowledge structures visible in a dynamic study environment even less educated and less motivated people have now a key to unlock the doors to Jewish traditions and knowledge preserving strategies.

Every document represented in the browser has different parameters that can be manipulated by the reader in the study environment to give further information on-demand. The parameters are visualized by checkboxes in a non scrolling frame. Thus the chosen parameters are visible all the time. Additionally, the given parameter setting is saved when the user changes the document, enabling her/him to follow a chosen path of study through longer units of text.

This successful use of metadata was one motivation for a similar approach in designing the VEL. But also our domain knowledge about entrepreneurship education and our computer science background influenced many design decisions as well as the cooperation with Kurt Fendt from the MIT. We used three semantic description dimensions to unveil the knowledge structures in the interviews with actors from the entrepreneurship community. First, we have the people in the entrepreneurial networks as one dimension. Second, we have the different stages of a startup, from idea and team building to the final exit of the founders of the investors. Third, we use a categorical schema (motivation, time and place, technology etc.) which we developed from our field studies at the Boston Route 128 area where we interviewed 30 people in the local entrepreneurial networks. The categories describe the interview sequences in the XML database and are reflected in the user-interface thus guiding the student while studying the presented now non-linear material. Motivated by a complex task the categories are both a starting point for exploring parts of the material but also an anchor for classifying a single multimedia sequence in

4. Discussion

For the development process the use of MPEG-7 as a metadata description standard was crucial for the Virtual Entrepreneurship Lab. With no other metadata standard we could combine multimedia content description and a semantic coding of the video material as efficient and comprehensive as we did it with MPEG-7. All the segments then were stored in the XML database where we can retrieve them in the learning environment. Even the collections working as personalized digital libraries or material collection for essays were stored in the MPEG-7 format. It was not necessary to extend the standard for any design or implementation task. From a technological point of view the existence of MPEG-7 helped us in realizing the learning environment but the knowledge to handle non-linear learning materials is partly originated from the people who edited the Babylonian Talmud.

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the greater context of the task. So, metadata are both guiding the design process of

(multimedia) learning environments and the learning process in these environments which is also true for the editing and reception process of the Babylonian Talmud. 5. Conclusions and Outlook

In this paper we presented and discussed two prototypical learning environments. . We have no sufficient empirical data so far but plan to incorporate the learning environments in our future classes in the humanities and entrepreneurship education. From the discussion it should be clear that the availability of multimedia metadata standards allows the development of learning environments which reflect the state of art in didactics and disciplinary research. Complex, multidimensional representation of semi-structured data can be tackled by using developed or available DTD or schemes. By relying on metadata standards we are open for new learning modules, other environments and further developments. Both environments have been used in demonstrating teaching situations and both of them were presented at international and national conferences of the involved disciplines. By fully understanding the use of metadata in the design processes and learning process in learning environments we hope to identify a model core common to all these processes and which we can extend for specific application domains of design and learning. 6. Acknowledgements

This work was supported by German National Science Foundation (DFG) within the collaborative research centers SFB/FK 427 “Media and cultural communication” and SFB 476 “IMPROVE“. We like to thank our colleagues in the center for the fruitful discussions. 7. References [1] Anderson, R.; Dickey, M.; Perkins, H.: Experiences with Tutored Video Instruction for Introductory Programming Courses, SIGCSE Bulletin, 33(1): 347-351, 2001.

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