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November 1998DIDASCALIAPage 1 ReLaTe Remote Language Teaching using videoconferencing.

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Presentation on theme: "November 1998DIDASCALIAPage 1 ReLaTe Remote Language Teaching using videoconferencing."— Presentation transcript:

1 November 1998DIDASCALIAPage 1 ReLaTe Remote Language Teaching using videoconferencing

2 November 1998DIDASCALIAPage 2 Background Collaboration between Exeter and University College, London –Exeter: Project Pallas (Humanities Computing) –UCL: Dept of Computer Science Early example of Internet videoconferencing Started 1994 ReLaTe: specifically for language teaching –BUT also used for wide range of educational applications

3 November 1998DIDASCALIAPage 3 Videoconferencing over UK SuperJANET network SuperJANET links all UK universities High speed backbone –155 or 34 Mb –10Mb SMDS to other sites

4 November 1998DIDASCALIAPage 4 ReLaTe trials Tutors and students - at any UK university –initially just Exeter and UCL –subsequently others, including Aberysytwyth

5 November 1998DIDASCALIAPage 5 Internet videoconferencing: background Early development - CU-SeeMe –available from Cornell University –commercial version now from WhitePine NetMeeting –freeware from Microsoft Initial versions limited to one-to- one Now allow multi-way via MCU/reflector technology

6 November 1998DIDASCALIAPage 6 ReLaTe: MBone videoconferencing MBone (Multicast Backbone) Like other Internet video- conferencing - uses IP protocols Is an overlay network that enables multimedia to be sent efficiently over the Internet Particularly important for multiway videoconferences Mbone tools - freely available

7 November 1998DIDASCALIAPage 7 Hardware requirements System runs on: PCs (Windows 95 or Linux) Unix workstations Small hardware requirements: Sound card… –but full duplex problems Camera and video capture board –Hauppage camera and Win/TV board on PCs

8 November 1998DIDASCALIAPage 8 ReLaTe session

9 November 1998DIDASCALIAPage 9 Individual MBone videoconferencing tools Video - vic –developed at Lawrence Berkeley Labs, California Audio - rat –developed at UCL –repairs packet loss through redundancy Shared Workspace - wb –developed at LBL –not available for Windows 95 (no source) Shared Text Editor - nte –developed at UCL

10 November 1998DIDASCALIAPage 10 Screenshot of ReLaTe session

11 November 1998DIDASCALIAPage 11 ReLaTe interface Much easier for novice users to control than multiple windows Has maximum of 4 or 8 users –if four, can click on one to give bigger window –powermeter beside each window for visual indication of who is speaking Audio controls –overall volume for input and output Shared workspace –Switch between whiteboard and text editor –colour shows who is adding annotations

12 November 1998DIDASCALIAPage 12 Advantages of MBone desktop videoconferencing No studio needed, use in own office Uses existing network infrastructure Platform-independent Uses readily-available hardware Software: free, in public domain Conserves network bandwidth Multiple video streams

13 November 1998DIDASCALIAPage 13 Disadvantages No reserved network bandwidth - quality very variable Video - not high quality –frame rates often only 4/5 frames/second Software coding/encoding means high-load on CPU Lots of network and system configuration required –need for MBone routers to be installed –hard to control on large bridged or switched networks

14 November 1998DIDASCALIAPage 14 Comparison with other forms of videoconferencing Compared with ISDN –ISDN guaranteed quality, but recurrent line costs, and multiple video streams not easy to achieve Compared with broadband ATM –ATM gives MUCH better quality and guaranteed quality, but much greater bandwidth demands –MBone - relatively small bandwidth demands MBone - relatively low bandwidths –80-100K for each video channel –60K - each audio channel –eg 4 participant conference takes 0.6 Mb/sec

15 November 1998DIDASCALIAPage 15 Coping with variable quality Audio quality much more critical than video –users can cope with video being jerky or stopping Video - still useful even at low frame rates –gives way of judging reactions, body language etc Audio tool - redundancy –sends second copy of each audio packet –if first packet lost or delayed, copy played out instead –enables sessions to continue even when considerable packet loss

16 November 1998DIDASCALIAPage 16 Language teaching trials ReLaTe system - now used for many trials –mostly specialist short courses, eg French for Lawyers, Mandarin –some longer, accredited courses eg students in second year of Intermediate French –results promising, but small numbers (4 students –taught in two groups of 2) make direct comparisons difficult

17 November 1998DIDASCALIAPage 17 Feedback from language teaching trials (1) MBone videoconferencing - good for small group tutorials –where genuine two-way interaction Seems less good for lectures –send copies of videotapes to remote sites instead? Variable quality of audio and video –problematic, but tutors and students coped OK –lip synchronisation desirable, but not essential for most types of language work; needs high video rates to work satisfactorily

18 November 1998DIDASCALIAPage 18 Feedback from teaching trials (2) Importance of shared workspace –whiteboard no longer solely belongs to tutor –students prize ability to add comments –perceived as very important for language work Integrated interface - well received Importance of full-duplex audio –tutorial teaching doesn’t flow if have to ‘click to talk’ Effect on tutorial styles –tutors seem to need more directed style, eg asking specific students, rather than throwing question open

19 November 1998DIDASCALIAPage 19 Feedback from teaching trials (3) Group dynamics - very interesting –seeing your own image on screen - eg looking bored! –students feel they know remote tutor, even when never met them face-to-face –tutorials - seem more concentrated Physical constraints –eg headsets tiring after some time

20 November 1998DIDASCALIAPage 20 Integration with other technologies Use of Web material –tried discussing material on Web, but synchronisation problems if each user has own Web browser –read individual Web pages into whiteboard, which worked very well Use of video clips –play out video clip into conference, instead of one participant –need better quality, because more movement than ‘head and shoulders’ view of live participants

21 November 1998DIDASCALIAPage 21 Future teaching developments….? Need for students to be able to work on own –eg like language laboratory mode, where tutor listens in –NetMeeting, gives ability for tutor to see student running application (eg CALL package) on local computer –alternative - use of multi-way Web browsers Need for tutorial to split into sub- groups –tutors want ability for small groups of students to be able to work without tutor - and then come back to original group and discuss results

22 November 1998DIDASCALIAPage 22 European potential Gives possibility of access to foreign tutors - and direct access to foreign students MBone - international network –technically feasible, but in past, bandwidths too low TEN-34 network –EU-funded infrastructure –links European research networks

23 November 1998DIDASCALIAPage 23

24 November 1998DIDASCALIAPage 24 European trials ReLaTe - carried out initial trials with Germany –University of Wuerzburg –problematic, but sufficiently successful to try further work… –problem of low multicast limits imposed by networks, even when high total bandwidths DANTE - soon moving to 155MB –for details, see:

25 November 1998DIDASCALIAPage 25 Future technical scenarios New versions of IP protocol - gives guaranteed Quality of Service Greater use of H.323 tools –eg NetMeeting, CU-SeeMe –once they support multi-way conferences adequately Other challenges –handling large multi-user tutorial/seminar style videoconferences –eg many thumbnail windows, plus voice activated larger window?

26 November 1998DIDASCALIAPage 26 Some Web addresses Videoconferencing tools used in ReLaTe - SHRIMP project –http://www-shrimp.cs.ucl.ac.uk/shrimp/ NetMeeting –http://www.eu.microsoft.com/netmeeting WhitePine CU-SeeMe –http://www.wpine.com/products/CU-SeeMe WhitePine MeetingPoint –MeetingPoint is Multipoint Controller software –http://www.wpine.com/products/MeetingPoint

27 November 1998DIDASCALIAPage 27 And (at last) THE END ReLaTe –http://www.ex.ac.uk/pallas/relate/ John Buckett - University of Exeter


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