e-chalk: a lecture recording system using the chalkboard metaphor...

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E-Chalk: a lecture recording system using

the chalkboard metaphor

1. INTRODUCTION

Using conventional authoring systems, the ratio ofproduction time versus duration of the producedlearning unit is typically a two to three digit num-ber. Generally, this is not economically viable, espe-cially as content of university lectures changesquickly. A cause for this tremendous effort is thattraditional teaching know-how does not easilymatch contemporary authoring tools. Besides tech-nical efforts, it requires huge amount of work tostructure pedagogical content for the web. Tryingto avoid these expenses, many universities use merevideo capturing of their lectures. This approachdoes not only need technicians present during therecording to handle the camera and the audio hard-ware, but also standard Internet video web casttools are inadequate for this kind of content.Writings and drawings, from slides or from a black-board, are not encoded appropriately. State of theart video compression relies on dropping out thehigher frequency parts of the images resulting in

the loss of sharp edges. Either content becomesunreadable, blurry or the video stream consumeshuge bandwidth.

Looking instead for established teaching tech-niques, one finds the chalkboard has been anunmatched teaching tool for ages in many disci-plines. Learners can see how ideas are developedrather than being overwhelmed with final results.This inspired the development of the describedsystem called E-Chalk (WWW).

A good chalkboard lecture should automaticallyresult in a good e-learning lesson. The goal is topreserve the pedagogical advantages and the easyhandling of the traditional chalkboard, whileextending its reach to distance learning. The sys-tem tries to enhance teaching quality in the class-room by allowing the instructor to integrate multi-media elements. During classroom teaching thelecturer works directly on a pen-active display oruses a digitizer tablet. At the same time, the lectureis being saved and transmitted live over theInternet with negligible additional effort. The

Interactive Technology & Smart Education (2004) 1: 9–20© 2004 Troubador Publishing Ltd.

Gerald Friedland, Lars Knipping, Joachim Schulte and Ernesto Tapia

Institut für Informatik, Freie Universität Berlin, Takustr. 9, 14195 Berlin, GermanyEmail: {fland,knipping,tapia}@inf.fu-berlin.de, [email protected]

This article describes a system that produces web based learning modules as a by-product of regular classroom teach-ing. The lecturer uses a pen sensitive display in place of the traditional chalkboard. In addition to drawings, the elec-tronic chalkboard handles a range of multimedia elements from the Internet. The system records all actions and pro-vides both a live transmission and a replay of the lecture from the web. Remote students follow the lecture looking atthe dynamic board content and listening to the recorded voice of the instructor. Several use cases of the system aswell as a systematic evaluation in two universities are presented.

Keywords Lecture recording system, board metaphor, evaluation, use case

VOL 1 NO 1 FEBRUARY 2004 9

system transmits audio, video, and the animatedboard image of the lecture (illustrated in Figure 1).Remote students only need a Java enabled Internetbrowser without additional plugin. They can alsoobtain a print out of the lecture, since a PDF file isgenerated as a static copy of the board content. Foran optional postproduction of lectures, a programcalled Exymen has been developed. Among otherfunctionalities, it allows one to change the audiotrack on a recorded lecture and to fix errors in theboard content.

2. METHODS FOR LECTURE RECORDING

The following paragraphs present a small overviewof systems currently used for creating distance edu-cation classes.

2.1 Video conferencing systems

Lecturers wanting to transmit a class often use avideo conferencing solution. However, video con-ferencing systems have not been created for teach-ing explicitly. Their conception assumes a sym-metric communication and relies on all partici-pants having equivalent hardware. Great effort isspent transmitting audio and video, but convinc-ing concepts for the transmission of teaching spe-cific content, such as board drawings, are notavailable.

2.2 Internet video streaming systems

Educators often rely on conventional videoencoders and players, two of many examples areWebcast Berkeley (WWW) and iLectures(WWW). The main scope of commercialencoders, like Windows Media Encoder,RealVideo, or Quicktime, is the transmission andarchival of audio and video data. Sometimes theyinclude the synchronized display of presentationslides. Of course, the latter requires postproduc-tion efforts. As described above, video encodingitself is not suitable for the display of slide orboard writings. Using a naive recording setup thesesystems produce poor audio and video recordingsfrom live lectures as their codecs assume a cleansignal. In practice, one needs high quality soundequipment and technical staff to eliminate audi-ence noise, reverberation effects, changes in illu-mination, etc.

2.3 CSCW tools

Several tools for working distributedly on a sharedscreen are available. Many digital whiteboard hard-ware comes with such a computer supported col-laborative work tool. They are neither designed forteaching nor for production purposes but for desk-top sharing with annotations. If they supportarchiving, they save a static screenshot.

2.4 Lecture recording tools

Several applications record a presenter’s desktopwith annotations, audio, and video. See for exampleLecCorder (WWW), Lecturnity (WWW),Camtasia (WWW), Classroom 2000 (WWW) andAbowd (1999), or AOF (WWW). Using thecomputer desktop as a lecture medium has severe

Friedland et al.: E-Chalk: a lecture recording system

INTERACTIVE TECHNOLOGY & SMART EDUCATION10

Figure 1 E-Chalk’s idea as an E-Chalk sketch

Figure 2 Lecture containing plot from a computer algebrasystem


disadvantages. The idea of the desktop metaphor isto be a virtual extension of the physical desktop,meant to be used with a mouse and a keyboard byone single person and not to be shared with anaudience. The universality of this paradigm turnsinto a drawback in the lecturing situation. Forexample, technical details such as browsingthrough the local file system or error messages arevisible to everybody. This does not only put pres-sure on the lecturer but is also distracting for learn-ers.

Consequently, recording slide presentations pre-dominate, hiding the desktop. While this approachimproves the situation, the authors think slideshows are still not adequate for domains of teach-ing, where complex trains of thoughts are to bedeveloped by the instructor and followed by thestudents, like in science. Another differencebetween presentation and lecture is, that presenta-tions have to be prepared in detail and concentrateon results. Many professional lecturers are able tosimply walk to the chalkboard and start up a spon-taneous talk with a high degree of interaction withthe learners.

Most lecture recording tools require the remotelearner to install a special receiving software1, usu-ally designed as a browser plugin. This introduces apsychological barrier for first time users – comparefor example Nielsen (1999). Moreover, remotelearners often do not have the skills or even thepermissions (for example on campus computers) toinstall such a client software.

3. THE E-CHALK SYSTEM

3.1 In the lecture room

The main objective is to present teachers with theenvironment they are familiar. The lecturer shouldbe able to step into the classroom and start teach-ing on the board without extra effort.

Having started E-Chalk, the system’s user inter-face metaphor changes from a computer desktop toa chalkboard. The computer screen becomes a dis-play for more than one person. The mouse isreplaced by a pen-like input device and the use ofthe keyboard is avoided as much as possible (forconcrete hardware solutions – see section 4). Thesoftware transforms the screen to a black surface2

where one can draw using different colors and penthicknesses. The board can be scrolled up anddown vertically, providing the lecturer with a virtu-al unlimited surface to write on. Instead of using adesktop-style scrollbar, two scroll points are provid-

ed at the top and at the bottom of the screen (seeFigure 2). The user grabs the board at a scroll pointwith the pen and drags the board up or down.

The system allows the user to paste images fromlocal hard drive or the Internet. Mathematicalrequests can be processed using an interface tocomputer algebra systems (such as Mathematica byWolfram Research or Maple by Waterloo Maple,Inc), partially by using a handwriting recognition,see section 3.1.1. Also any CGI script in the webdelivering text or pictures can be queried.

All these actions on the board are tracked. Thedevelopment of the board content can be viewedby a remote learner, both as a live transmission andas an asynchronous replay. The voice of the lectur-er can also be recorded. These two data streamscapture already most of the teaching substance.The distance learner is provided with a live scriptwhere teacher’s side notes are not lost. Optionally,a video stream of the instructor can be used to givethe remote lesson a more personal touch.

The system does not require the user toexplicitely trigger a save. Everything is automati-cally stored for web browsers. E-Chalk can also beconfigured to store the lecture in a database or alearning management system3. The entire softwarehas been written in Java and runs on Linux, MacOSX, and MS Windows platforms.

3.1.1 Handwriting recognitionAs mentioned above, keyboard typing should beavoided in the board metaphor. Its usage interruptsthe lecturer’s workflow. As a result, a handwritingrecognition was included in E-Chalk right from thevery beginning (cf. Rojas et al., 2001a, 2001b;Friedland et al, 2003). While the early version couldonly handle simple arithmetic expressions, it hasnow moved to more complex mathematical formu-las, see for example Figure 4.


Figure 3 Above: Main horizontal baseline and clusters ofsymbols. Below: Final tree of spatial relations

When a set of strokes is recognized as beinggrouped into a symbol, it is preprocessed and clas-sified. A special symbol is reserved to mark the endof an expression. It is a tick symbol, reminding oneof the the symbol printed on the enter key of usualcomputer keyboards. If the classification resultgives as output the “end” symbol, the system analy-ses the complete list of recognized symbols. Twodifferent groups of symbols are recognized by theprogram. The first one consists of the digits 0 to 9,the arithmetic operators +, –, *, /, √, the parenthesisand the ‘end’ symbol. The second group is formedby the variables a, b, c, m, n, x, y, z, θ and ∆, the con-stants e, π and ∞, and the operators ∫, ∑, ∏, ∂ andthe differential operator d in the integral. If anexternal computer algebra system is connected tothe E-Chalk system, all the symbols are recognizedand passed to the algebra system, otherwise onlythe first group is recognized and then processed bya basic calculator included in E-Chalk.

The construction of the formula is made follow-ing two main steps: recognition of symbols andconstruction of the hierarchical structure in themathematical expression. The recognition of on-line characters is done using Support VectorMachines (see Tapia and Rojas, 2003b), a recenttechnique for classification and regression based onthe research of Vapnik and Chervonenkis (seeVapnik, 1998). The structure of the mathematicalexpression is determined as follows: Mathematicalnotation can be described as a hierarchical struc-ture of nested baselines, which represent a hori-zontal arrangement of symbols in the expression.Exploiting the left-to-right reading of mathemati-cal expressions, the main baseline is constructedand clusters of symbols not belonging to the mainbaseline are found using a minimum spanning treeconstruction based on symbol dominance, making

an analysis on the proximity of symbols (see Figure3). Symbols in the main baseline have pointers tothe clusters, depending on the mathematical rela-tion (above, below, right, superscript, subscript,subexpression) they satisfy. We apply recursivelythe method on clusters as long as no more symbolsare left when the horizontal baseline is constructed(see Tapia and Rojas, 2003a).

3.1.2 Audio and video streamingEarly versions of E-Chalk used the World WideRadio (WWW) system (see Friedland et al., 2002)to stream and archive the voice of the lecturer. Thiswas similar to the common approach for on-the-flystreaming and recording of university lectures:software defined radio systems combined withvideo and slides. World Wide Radio was designedfor streaming web radio and its principal design canbe compared to other approaches, like RealAudio,Quicktime, or Windows Media Player (Manhart,1999). The main difference is that WWR is imple-mented in Java. As a result it can only use technol-ogy that exists on every platform, operating systemspecific codecs for example cannot be integrated.On the other hand, combinability between stan-dard Internet streaming systems is missing, forexample, if one wants to combine a video confer-encing system with E-Chalk. Usually, severalstreams are combined by just starting differentapplications. Of course, no synchronization thenexists between the streams.

E-Chalk now uses a system where any streamingserver is modeled as a flow graph, Figure 5 showsan example. The graph consists of five basic typesof nodes: Sources, Targets, Forks, Mixers, andPipes. Technically, any component that wants tolive inside the graph becomes a node by inheritingone of these five superclasses4. The graph thatglues these components is described by an XMLfile. Nodes are described via general properties,for example, to tell the system to select someaudio codec that compresses down to a certainbandwidth. The system then looks for an appro-priate codec, first locally and then in the Internet.The structure of the graph can be changed and thenodes can be updated while the system is running.All data is being synchronized automatically. Thisallows clients to let the server be updated on the



Figure 4 E-Chalk’s handwriting recognition (developer’s view)

Figure 5 A simple streaming server graph


fly to match their requirements, instead of forcingthe client to load an updated module. For example,nodes for both WWR and Windows Media Playerexist. When a client connects with eitherWindows Media Player or with the Java basedclient for a live connection, the E-Chalk streamingsystem updates itself and loads the appropriatemodules.

All the nodes are realized as services inside anenvironment, standardized by OSGi (WWW). Themechanism originally comes from the field of ubiq-uitous computing and specifies how to load,update, and delete software components from theInternet, while a system is running (OSGi, 2002).E-Chalk uses the Oscar5 OSGi implementation(Hall and Cervantes, 2003).

3.2 Optional postproduction

Exymen was created as an editing tool for arbitrarymedia formats (Friedland, 2002b). It offers an openprogramming interface (API) which allows toextend the editor for any multimedia format andfiltering effect. The extension mechanism is basedon Oscar/OSGi (see section 3.1.2).

Among the formats implemented are those forediting E-Chalk lectures, as shown in Figure 6.This allows to postprocess recorded lectures. Aspecial problem of the board stream is that eventsdepend on each other in both time and space andcannot be edited naively. The implementationtakes care of the resulting constraints (Friedland,2002a). When the E-Chalk streaming system intro-duces a new component (see section 3.1.2) it is alsoautomatically used for editing in Exymen, as they

use a compatible component management andupdate mechanism.

Another extension of Exymen allows the cre-ation of animated web slide shows with audiotracks. See the Giove Project (WWW) for anexample. 3.3 Distance learning

When remote students open E-Chalk’s generatedwebpage of a given course with a browser, replaystarts in the form of self synchronizing JavaApplets. One Applet is started for every datastream present: board, audio, and video. AnotherApplet, a control panel, is provided for navigationin archived lectures (see Figure 7). All these Appletsrun in a standard Java enabled browser6, withoutrequiring the user to download a plugin. As anoth-er advantage this solution is completely platformindependent.

The audio system uses lossy compression andbuffering to guarantee interruption free transmis-sion. The required bandwidth for the transmissionof audio and dynamic board content is up to 64kbps, depending on the selected audio quality. Thenetwork traffic generated by the board content isnegligible compared to the traffic needed by theaudio signal, since the board uses a vector format.Using a video stream requires further 64 kbps. Forthe compression of the video signal a simple codecis used, based on difference images and JPEG. Astatic copy of the final board image as Adobe PDFfile is also included for the students to print – seeFigure 8.

4. USE CASES

To use the E-Chalk Software in the classroom, one


Figure 6 Editing an E-Chalk lecture with Exymen Figure 7 E-Chalk lecture as seen in a browser

needs a pen based input device and a wide display.The display should offer good contrast, so that thevisual quality can be compared to a real chalkboard,e.g. one does not want to darken the room for thelecture. Mainly, the following device configurationsare in use: • Digitizer tablets or tablet PCs with LCD projector

The lecturer writes on a tablet while the com-puter screen is projected against a wall.Digitizing tablets are comparatively cheap andeasy to transport. The teacher can look at theaudience while writing, if a tablet with integrat-ed display is used, which also eases hand-eyecoordination.

• Digitizing whiteboardsSeveral companies distribute digitizing white-boards. These are wide, perpendicular mounteddigitizing tablets (up to 8” diagonal). The screencontent is displayed on the surface by an LCDprojector.

• Retro projectors with pen trackingThe advantage of using a retro projection sys-tem as wide display device is that nobody inter-feres with the projection beam. Contrast andluminance being much better than those of anLCD projector they are usable without darken-ing the room. Disadvantages are their heavyweight and the high purchase costs.

Having many students in a lecture room, a verybig display surface is required. One can use a digi-tal whiteboard or a digitizer tablet as writing sur-

face plus an extra projector that projects the boardcontent widely. This way, board content is even bet-ter visible than on a regular chalkboard. TheTechnische Universität Berlin uses this setup regu-larly – see Figure 9.

For smaller seminars one can use a setup withseveral digitizer tablets, enabling students to inter-act on the board from their seats. In the caseshown in Figure 10, the geology lecturer uses a rearprojector and the students use small digitizertablets to work on geographical maps.

A handicapped professor in Arabic linguisticswas glad to be able to give a chalkboard lecture



Figure 8 An E-Chalk lecture replay and the corresponding PDF page

Figure 9 Mathematics lecture at the Technische UniversitätBerlin using a digital whiteboard and an extra projector


while seated using a digitizer tablet for himself,instead of writing on the rear projection screen.This scenario is also useful for a German highschool: The computer room of this school is sosmall, that neither a chalkboard nor tables for thestudents which are big enough for a computer andwriting space, fit in. The teacher uses E-Chalk witha digitizer tablet and projects the board contentonto the wall. The generated PDF of the lecture isprinted out at the end of the lecture, so that stu-dents can get a copy of the class even though theydo not have enough space for writing.

The Freie Universität Berlin also used E-Chalkin combination with videoconferencing systems tohave audiences in different locations at the sametime. The chalk content is sent parallel to the videoconferencing stream (see Figure 11). This enables

students to follow remote chalkboard lectures andcommunicate with the instructor.

It is also possible to give a lecture at home andpresent it later (see Figure 12). School teachersfound this a practical feature because they can eas-ily create classes for the students to see at home.

5. EXPERIENCES AND EVALUATION

Since the summer term 2001 the computer sciencedepartment of the Freie Universität Berlin usesE-Chalk for courses regularly. Since the winterterm 2002 the mathematics and physics depart-ments of the Technische Universität Berlin hasequipped eight lecture halls and seminar roomswith E-Chalk. In the summer term 2003, about1100 students were taught with E-Chalk at thesetwo universities. The authors counted about 700installations of E-Chalk world wide (as ofNovember 2003), 50 of them are known to be usedregularly. A field study has started to evaluate theuse of E-Chalk and its improvement for classroomteaching (Schulte, 2003). The results are summa-rized below. The Berlin school department is evalu-ating whiteboards using E-Chalk in Berlin elemen-tary and secondary schools. Within the project‘Computer in die Schulen!’ (CidS! (WWW)), twelveschools were equipped with electronic boards sinceearly 2003. One of them is shown in Figure 17.

5.1 Evaluation

5.1.1 MethodsThe evaluation was constructed as a field study


Figure 10 Geology seminar at the Freie Universität Berlinusing rear projector and several tablets

Figure 11 A robotics lecture sent from Stanford Universityto Freie Universität Berlin

Figure 12 Using a microphone and a digitizer tablet classlessons can be created at home

under real life conditions. Its emphasis lies in theexplorative description of leading questions, suchas the usage and acceptance of the software, as wellas possible effects on the students’ motivation forstudying. An examination has been conducted tofind out effects on students’ exam results. Theseaspects were evaluated throughout the summerterm 2003 in six selected lectures7 at both, theTechnische Universität Berlin (TU Berlin) and theFreie Universität Berlin (FU Berlin).

For some of the leading questions the develop-ment of answers through the term was examined.595 questionnaires were evaluated and 52 studentswere identified to have answered the questionstwice, in the beginning and in the close of the term.Their responses were examined for changes in theirattitudes.

To find out E-Chalk’s influence on exam results,students were asked for their usage intensity forpreparation. Some lecturers were selected bychance to be interviewed. One lecture used a learn-ing management system7 giving the evaluator sta-tistics on the student’s access on E-Chalk.

5.1.2 FindingsAt the TU Berlin, students preferred sitting in thelecture hall over remote replay. Still, the remoteusage at both universities intensified during theterm, see for example Figure 13. The rising intensi-ty indicates students’ preparations of their upcom-ing exams.

However, no significant correlation betweenexam results and usage could be found (see Figure14). In all user categories almost the same grade hasbeen achieved. The evaluation report explainedthis with influence of external factors. The authorof the report suggests further examination byforming two groups with the same external condi-tions differing only in the usage of E-Chalk.

At the TU Berlin courses, the printable PDF waspreferred to the replay of lectures by most students.

The cause is that no audio signal was recorded atthe TU Berlin due to infrastructural problems withtheir audio equipment. Students of the FU Berlinused the PDF and the replay on an equivalent level.A small, but not statistically significant tendencyexists, that students reduce copying board contentscompared to regular courses (see Figure 16).

At the TU Berlin both mobile and fixed digitalwhiteboard installations were tested. Experience



Figure 13 E-Chalk usage at the evaluated FU Berlin coursefrom June, 10th until the day of the exam on July, 14th

Figure 14 Exam results in correlation with the usage of E-Chalk (1.0 is the best grade)

Figure 15 Didactic quality of E-Chalk courses


showed mobility is not desirable. Even a slight, pos-sibly unintentional move, requires the whiteboardto be recalibrated.

The usage of E-Chalk did reveal neither positivenor negative effects on the students’ motivation toprepare for the lecture. Quality of the software wasjudged positively by the students. Didactic qualityof the courses had been perceived well compared toregular courses (see Figure 15). Students welcomedthe extra flexibility.

Lecturers’ skills regarding the software improvednoticeably during the term, as shown in Figure 18.Lecturers needed between two and four lectures toget fully accustomed. The evaluation report judgesthis as an indication for the easy handling of thesoftware.

5.1.3 Results and interpretationsRecorded lectures are also useful for students notbeing able to be present in the classroom for dif-ferent reasons, for example scheduling collisions.The most frequent use of recorded lectures is forexam preparation. The live transmission of the lec-ture can also help to relieve classrooms. However,experience showed that, compared to replay ofarchived lectures, the demand for live transmis-sions is marginal. The following points summarizefurther evaluation results:

• Overhead work to use the system for lecturing islimited to the start of the term for setup.

• The lecturer can easily integrate material fromformer terms.

• Traditional chalkboard skills directly map intogood E-Chalk lectures.

• In practice the use of plain drawings and writ-ings predominates. Features like the integrated

computer algebra system or calling CGI scriptsare used rarely.

• If audio has been recorded with the lecture, stu-dents use both, the E-Chalk replay and the PDFprintout.

Of course, one should not think that the systemincreases the quality of teaching just by its exis-tence. Teachers have to use it properly and stu-dents still have to study.

6. ONGOING DEVELOPMENT

Producing distance lectures with high fidelity audiorequires additional man power. This is to be substi-tuted by intelligent software. Usually a high qualityrecording and transmission of the lecturer’s voicerequires support from two kinds of persons:


Figure 16 Copying of the board content

Figure 17 English lession at a Berlin school

System administrators who set up and combine therequired components (such as codecs, server com-ponents, and web sites) and audio technicians whocontrol the quality of the recording. The self organ-ising streaming system described in section 3.1.2already takes over a big part of the administrationworkload. Section 6.1 describes the approach forproviding a software audio technician. Section 6.2presents the authors’ current work to optimize theusage of the video image in E-Chalk.

6.1 Studioless audio recording

Lecture halls and seminar rooms are not audiorecording studios. Therefore it is not possible toproduce professional quality recordings by justplugging a microphone into a soundcard and start-ing the lecture. Recording studios have a lot moreequipment and qualified audio technicians arealways present. The system’s audio recording assis-tant helps to prevent the most common problemsby giving direct feedback to the instructor, forexample showing a warning when the remotemicrophone is out of battery. The more sophisti-cated task is to develop software to control theinput gain and to use proper realtime filters forachieving high quality recordings.

6.2 Transmitting gestures

E-Chalk lectures which include a video of theinstructor share a psychological problem with con-ventional distance lectures consisting of slides plusvideo stream. Although every human being onlyhas one center of attraction (see Baar, 1988), theattention of the remote student is demanded by

two areas of the screen: the video window and theboard or slides area. Hence a project has been start-ed to separate the video image of the lecturer fromthe background. The image of the instructor canthen be laid over the board, creating the impres-sion that she or he is directly working on the screenof the remote student. Mimics and gestures of theinstructor are now appearing in direct relation tothe board content. The image of the lecturer canbe made semitransparent or even turned off (seeFigure 19).

7. SUMMARY

With the system presented here it is possible toproduce distance lectures as a by-product of class-room teaching. The distance lectures are not sub-stituting classroom teaching but supporting it.



Figure 18 Quality of the lecturer in using E-Chalk – development in the term

Figure 19 Semitransparent instructor over board image(montage)

Students are helped to rework the materials with aliving and active script. The remote student doesnot have to spend great technical effort to receivethe lecture. Only a browser is used and no specialsoftware has to be installed. All substantial infor-mation in the form of audio and dynamic boardimage can be received with low bandwidth require-ments.

The board is a new GUI metaphor. At the timebeing, the desktop is the dominating user interface.This metaphor, however, is designed for the small,personal screen that integrates in the physical writ-ing table. Even the pen computing approaches,which have become popular recently, are consid-ered only for personal displays. During the teach-ing situation, where a wide display is observed by agreater audience, the board is the proper metaphor.This way, the relation between teaching tool,teacher, and students is preserved, as it proved tobe valuable for centuries. The audience can trackthe instructor developing the subject on the board.The technical implementation of the teachingdevice is formed by the pedagogical needs, insteadof letting the device be purely driven by the tech-nical development.

Project members

Prof. Dr. Raúl Rojas conceived the E-Chalk systemand is head of the project.

Gerald Friedland and Lars Knipping areresearchers at the department of computer sci-ence at FU Berlin. They developed the E-Chalksystem.

Joachim Schulte is a student of communication sci-ences and performed the evaluation.

Ernesto Tapia is a PhD student at the FU Berlinand has developed the online handwritingrecognition.

NOTES

1. For example, Lecturnity (WWW), AOF (WWW)and Camtasia (WWW) require proprietary playersoftware. LecCorder (WWW) uses signed Java-Applets for replay.

2. Actually, the system can be configured for differentbackground colors. In practice, black is preferredbecause having the content shining instead of thebackground is less straining on the eyes.

3. So far, the authors experimented with an Oracledatabase and the learning management systemBlackboard.

4. This task requires a developer to overwrite ten or

less methods for building a wrapper to a streamingservice one wants to integrate.

5. The implementation can be found at http://oscar-osgi.sourceforge.net (last visited 13/11/2003).

6. The Applets need only Java 1.1, to avoid the require-ment of a Java upgrade for the browser, and theyneed not be signed.

7. At the Freie Universität Berlin, E-Chalk was evaluat-ed in a computer science lecture on NeuronalNetworks. At the Technische Universität BerlinE-Chalk was evaluated in the courses: Calculus II forEngineers, Introduction to Numerics, LinearAlgebra for Engineers, Numerics for Engineers, andIntroduction to Physics for Engineers.

8. The FU Berlin used the learning managment systemBlackBoard (WWW).

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studio, visited 11 November 2003 CidS! (WWW) http://www.cids.de}, visited 11 November

2003E-Chalk (WWW) http://www.echalk.de, visited 11

November 2003Classroom 2000 (WWW) http://www.gatech.edu/fce/

eclass, visited 11 November 2003Giove Project (WWW) http://www.giustiniani.org, visit-

ed 11 November 2003iLectures (WWW) http://ilectures.uwa.edu.au, visited 11

November 2003LecCorder (WWW) http://www.leccorder.com, visited

11 November 2003Lecturnity (WWW) http://www.lecturnity.com, visited

11 November 2003OSGi (WWW) http://www.osgi.org, visited 11

November 2003World Wide Radio (WWW) http://www.javaradio.de,

visited 11 November 2003



Gerald Friedland is researcher and instructor at the artificial intelligence group at the computer science department of the FreieUniversität Berlin and is working on streaming audio and video. He belongs to the ITSE board of editors and is a member of theDIN-NI 36 committe that cooperates with ISO SC-36 in creating e-learning standards. He received an MSc degree in computer sci-ence. His thesis was awarded the Best Paper Award by the German computer scientists association (‘GI’). As a high school studentMr Friedland was rankedfirst place at the state-wide young scientist’s contest (“Jugend forscht”) with a self developed Internetradio system.

Lars Knipping is a researcher and instructor at the multimedia group at the computer science department of the Freie UniversitätBerlin. He belongs to the ITSE board of editors and is a member of the DIN-NI 36 committe that cooperates with ISO SC-36 in creat-ing e-learning standards. Before joining the multimedia group, he worked as scientific consultant in a research project for a state-founded TV broadcaster, the “Sender Freies Berlin”. He received MSc degrees in both mathematics and computer science.

Joachim Schulte is a student of Communication Sciences, Psychology and Journalism at both the Freie Universität Berlin andTechnische Universität Berlin. He has recently finished his master thesis, “Evaluation of the usage of ‘E-Chalk’ in university lec-tures”.

Ernesto Tapia is a PhD student with the artificial intelligence group at the Computer Science Department of the Freie UniversitätBerlin. Funded with a credit-scholarship by the Mexican National Council for Science and Technology (CONACyT), he is working onmathematical formula handwriting recognition. Mr Tapia received an MSc degree in mathematics from the Centro de Investiga-ciones en Matematicas (CIMAT), Guanajuato, Mexico.

e-chalk: a lecture recording system using the chalkboard metaphor...

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