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Classroom-based Videoconferencing

 

 Introduction 

Videoconferencing can be a very effective and easy way to bring guest speakers into your classroom. There are two main technologies for doing this, ISDN and IP, discussed further in Appendix 1.

ISDN systems are usually based in broadcasting studios and conference rooms. Some Universities have teaching rooms with ISDN facilities. The advantage of ISDN is that it is high quality and is not competing with other network traffic for bandwidth. At Warwick there are no ISDN videoconferencing facilities suitable for classroom teaching.

IP systems work over normal Internet connections. The advantage is that it is easy and cheap to use. The disadvantage is that the quality is limited, and it used the University network, which has many other bandwidth demands placed on it. It can still be used effectively for classroom-based videoconferences. The steps involved are listed in appendix 2.

 Preparing for the videoconference

Time The need to establish a time is obvious, however, if you are working across time zones this can be difficult, particularly since time differences are constantly changing due to daylight saving. Some service departments require all booking information in GMT, not local time (which can be confusing during the summer). Time zone information is available on http://www.timeanddate.com/worldclock/

Contact numbers If you are using ISDN you will need the telephone number for the lead ISDN line. If you are using IP based systems you will need your contact’s IP address. If you are using iVisit you will need to have clarified which room you will be in, and have distributed the password for the room. It is always useful to have your contact’s/contacts’ telephone number(s) in case the connection fails to work.

Who's calling whom? This needs to be established when arranging the videoconference

Check software If you are using NetMeeting make sure that you and the students both have the same version.

Monitor settings If you are planning to link desktops, make sure that both monitors are set to the same desktop area (e.g. 800 x 600 pixels).

Check firewalls If you are using IP addresses to connect, check that you can access each other end through your and their firewalls. If you can’t, identify whose firewall is creating the problem by both calling a third party. Your (and/or their) IT department can create a “hole” in the firewall between your IP address and their IP address. For this both ends will need a static or fixed IP address.

Check permissions Sometimes firewalls are set up to allow high data transfer from staff machines only. If you are using a laptop it is likely that its IP address is not registered as a staff machine. If you have problems delivering a videostream to a web-mediated videoconference (such as Marratech or iVisit) this may be the reason. This will be resolved by requesting IT services to change the permissions of your laptop’s IP address.

Distribute documents If you are using a room-based videoconferencing system rather than a desktop-based one you may not have access to NetMeeting. Even if NetMeeting is being used, you may find that it is useful for the students to have a handout to refer to, or a video to view, during the session. Large media files are better distributed before the session than attempting to run them by sharing applications. Unzipping them during the session can also waste time. If the students are to be involved in discussions, enabling them to prepare beforehand can add a lot of value to the session. If possible a website with all of the resources is the best way to support the session

 Running a videoconference

The basics

These aren't specific to videoconferencing but are good pedagogical practice in any situation. However, because communicating via videoconferencing is more problematic than face-to-face, good pedagogical practice becomes even more important. Video and television are usually passive media, and the resemblance of videoconferencing to these tends to encourage passivity. Engaging students with purely didactic sessions is far more difficult with videoconferencing; the lack of physical presence of the lecturer, and their reduction to an image on a screen is even more demanding on students' degree and duration of attention than a face-to-face session. For this reason tutorials and supervisions tend to work better via videoconferencing than lectures and software demonstrations, since they are customarily more interactive and student-centred and are with small groups of students. Students’ involvement in the sessions can be encouraged through the following considerations:

What will the students have to do? What are the intended learning outcomes for the session?
  • Be clear about the purpose of the session
Break up the sessions with different media, with opportunities for feedback or with work the students can carry out within the classroom.
  • Vary activities and vary modes of presentation
An interesting and enthusiastic presentation will be make the work more engaging for the students.
  • Modulate tone and pace
  • Technical Issues

Voice-activation

Some software uses voice-activation to select who can be heard at any one time (sometimes called hands-free). It’s important that the person who isn’t talking deactivates the hands-free, otherwise any slight sound will cut-off the speaker. When you hand over to the other person to speak, you will need to click off the hands free to ensure they can be heard without interruption.

  • Ensure you have deactivated hands-free when you are not talking
  • Try not to limit non-essential sounds

Time delay and disabled duplex

A very short delay between one person talking and the person at the other end being able to hear what has been said can be experienced with some videoconferencing technologies. If you have disabled the duplex, there may also be a short delay as the system switches between a person stopping talking and being able to hear the other person. In face-to-face communication we leave small gaps for the other person to take up the conversation if they want to, if they don't we tend to carry on. In a videoconference the delay interrupts this subconscious exchange. The videoconferenced conversation can therefore often lapse into hesitations and interruptions. Although it creates a more stilted conversation, slow down the pace of the exchange and clarify handovers. This is particularly important if you have the duplex disabled, since it’s possible for the other person to entirely miss the first second or so of what you are saying.

You may also find that your speakers may cut out if you say anything. If the time delay due to the duplex being disabled is particularly long, then you might find that even a simple “yes” will halt the flow of the speaker at the other end for a second or more. You may consider a non-verbal gesture instead, however, nodding and shaking of heads will not be picked up unless the frame rate is very high. Use thumbs up or down instead, since a single frame can convey this, or another gesture if this one is inappropriate in the culture of the participants.

If you find you have created confusion by talking over each other, it is worth spending some time clarifying what has been said before moving on.

  • Explicitly hand over to the other person when you have finished talking
  • Leave longer pauses when handing over to the other person than you would in face-to-face conversations,
  • Wait until the other person has responded and clearly finished before continuing
  • Make static non-verbal gestures, not moving ones.
  • Leave the verbal response until the person has finished talking, otherwise it will cut out the other person
  • If you have been talking over each other, reiterate the key points to ensure clarity.

Camera position

One of the constraints to effective communication across videoconferencing is the inability to make eye contact, since the camera will always be in a different position to the screen. However, reducing the difference as much as possible will increase students' feeling of contact with the person at the other end.

  • improve sightlines as much as possible

Presentation

All the technologies offer the opportunity to view your own image, either as picture-in-picture or as a separate image. Some equipment is also not too adaptive to variations in volume.

  • Keep an eye on the image you are sending and ensure that you're always in shot.
  • Speak clearly.

Interruptions

An inevitable part of working from home or the office is interruptions from other people, the phone etc.. Feedback from sessions we have run indicate that these are not a problem, a short interruption and a bit of light relief usually have a beneficial effect, as long as the interruption is dealt with quickly. Breakdowns in the link are more problematic. Once the link is restored, reiterate what was being said before the break, to ensure that nothing has been missed, or check at what point the break occurred.

  • Don’t worry about interruptions, but deal with them quickly.
  • Make sure you re-cap after a break, so that nothing is missed.

Practise videoconferencing

If any of the participants are new to videoconferencing their first engagement will probably require their focus to be on the technology, not on the content. A preliminary session, or if this isn't possible, ten to twenty minutes at the start of your first session, will enable the students to familiarise themselves with the features of the software, and what videoconferencing "feels" like.

  • Allow your students (and yourself) some time to experiment with videoconferencing.

 Teaching Issues

Use the technology

Videoconferencing can also provide features that aren't available in face-to-face to enrich the sessions. Example are: sharing applications, such as jointly completing a spreadsheet or word file or viewing the same images or websites; providing exercises that exploit interactive programs; or using chat, the whiteboard or screen recording software to record particularly important parts of the session. It is particularly useful to type proper names and references into the chat window. If you are planning on both looking at a video file, use the file transfer function to ftp the file to the other end, rather than try and open it on your desktop and try and share the application. Better yet, send it before the videoconference so that they can pre-install it on their PC.

  • Share applications and documents
  • use additional software for student exercises
  • Use the chat window for proper names, references, or tasks
  • cut and paste the chat window to a word file and email it to the students later
  • don't try and share video applications, use file transfer to send the video file so that the students can run it from their PC

Delivery styles

Keeping a lecture interesting is more of a challenge via videoconference than face-to-face. Presentation skills such as modulating tone of voice, developing good questioning skills and building in activities to the session are even more important in order to compensate for the lack of physical presence.

  • keep it lively
  • encourage participation
  • break often

Structuring communication

Feedback must be more highly structured than a face-to-face situation. This is for two main reasons. Firstly, students cannot interrupt if the microphones have been switched off to avoid the echo problem described above. Secondly, the lecturer cannot adequately observe the students to detect any visual cues that they want to ask a question or are not following the lecture. The lecture therefore needs to be broken into very short sections with feedback specifically elicited from the students after, for example, each slide. Formalising the question asking, such as having a rota, can enable the less assertive students to have an input, but can be time-consuming. If students feel self-conscious, asking questions via camera or if the equipment constrains student questioning. A facilitator at the far end is always useful, since they can elicit questions, and clarify problems. Questions can also be submitted via a chat session running in parallel to the videoconference, or by mobile phone text messaging.

  • check frequently for understanding
  • wait for responses (even if it is just to confirm that there are no questions)
  • if time allows, ask for responses in canon, i.e. go round each student in turn inviting a comment
  • consider running other technologies in parallel to assist feedback, such as a chat session or CMS messaging
  • if possible, have a facilitator at the far end

Structuring the session

If you are presenting a lecture or software demonstration break it down into short sections (a maximum of 10 to 15 minutes) and have other activities between the sections, such as viewing a video, or working on exercises within the classroom, or simply a question and answer session. If students have prepared work (see Preparing for the videoconference above) then their presentation of their work can also be one of these alternative activities. Listing the sequence of events during the session enables the students to see where they are, adds coherence to the sessions and acts as a shared prop for you and the students in addition to the videoconference link. Having a handout also gives the students a break from concentrating on the screen. If your session requires a large didactic element consider videoing it beforehand and making the video available to the students before the session. This then leaves the videoconference session free for the students to interact with you, which is the purpose of the technology.

  • incorporate breaks away from the videoconferencing for different activities
  • provide a handout with the structure of the session and/or notes
  • give the students something to do (cf. preparing for the videoconference)
  • planning a purely didactic presentation? then send a video instead

Follow-up to the videoconference

In face-to-face situations students can obtain additional learning support on an ad hoc basis (usually by dropping in to the tutor's office). After a videoconference this is not so easily achieved. Opportunities need to be made available for the students to follow up with further work. If a website has been set up, additional resources can be placed there, such as FAQs or a discussion board. Chat sessions have also proved to be very popular.

  • Provide additional learning support using chat or discussion boards

bullet Appendix 1: Introduction to technologies

Hardware

ATM Asynchronous Transfer Mode. Packages, transmits and switches data to optimise the connection. Advantages: very high quality of image; dedicated lines. Disadvantage: very expensive.

ADSL Asymmetric Digital Subscriber Line. Uses the frequencies in telephone lines not used in regular telephone calls. Advantages: High quality image; dedicated lines; not very high cost. Disadvantages: BT is stalling implementation; BT is allowing very high contention4 which means if a lot of your neighbours install it, the bandwidth drops.

ISDN Integrated Services Digital Network. Advantages: High quality; dedicated lines. Disadvantages: High cost to install and use; BT responsible for maintenance so unless regularly used tend to be poorly maintained and therefore unreliable; location of ISDN connection tend to be into meeting rooms, not classrooms.

IP gateway systems Using a gateway system enables the user to connect any IP port to the ISDN line, in effect extending the ISDN link into any room with an IP port. Advantages: High quality; flexible use. Disadvantages: expensive equipment; experienced technical knowledge required to set up.

IP room-based systems Videoconferencing equipment that can plug into IP ports. Advantages: high quality, flexible, easy to operate. Disadvantages: expensive; does not have a dedicated line, so will have to share bandwidth with other users of the network.

IP desktop systems A computer with a camera attached. These can be used either for 1 - 3 students (sitting around the computer) or larger groups (by projecting the monitor image via a data projector). Advantages: easy to use; flexible; no cost; can use other applications with the image; does not require high bandwidth. Disadvantages: low quality.

Software

Webex A desktop conferencing systerm offered by IT Services.

IVisit This freeware can be downloaded from the iVisit website. Users all log in to the iVisit website and enter a pre-arranged room. Several users can share a room at the same time. A chat function is also available, which works better as a means of communication than audio.

 Appendix 2 Use of IP desktop systems for room-based videoconferencing

You will require:

  • PCs connected via IP to the Internet
  • a camera connected to the PC
  • videoconferencing software running on the PC
  • a data projector to project the image on the monitor onto a screen
  • microphone and speaker system.

The first three features are commonly used in standard desktop-to-desktop videoconferences. These are simply adapted for use in a teaching situation by the addition of a data projector and usually a microphone and speaker system for classroom use. In addition, a webcamera is not sufficient to view an entire class, so a camcorder is usually used, connected via a videobus to the PC. Note that this requires the use of a serial port so will not work on Windows NT.

If a network port is not available within the classroom you want to use, connections have been run successfully up to 40m from an IP port. The technique used was to connect two 20m CAT5 network patch cables using a network switch. This will, however, make higher bandwidth demands than a short connection (packets of data will be lost en route and so will be re-sent, requiring more bits per second).

Microphone position

Verbal feedback is a problem if the microphone is turned off to prevent echo (which is necessary if it is not possible to disable the duplex). In these situations particular attention must be paid to students' requests to ask questions. Where handheld microphones have been used participants have reported feeling very self-conscious about the process of passing round the microphone. Discussions cannot be relayed using a unidirectional microphone. Pressure zone microphones (flat mikes) are far more successful. In a dedicated videoconferencing room these should be ceiling mounted. Desk-mounted microphones can pick up extraneous noises such as paper rustling if participants are not careful around the microphone.

  • use omnidirectional microphones wherever possible
  • keep the microphones away from participants

Advantages

The major advantage of this method of videoconferencing is its accessibility. All of the equipment used in IP-desktop videoconferences is usually already available in the department or is purchasable at a low cost. The accessibility of the equipment means that the users have flexibility, and more importantly control, over the videoconference. In addition the technology is familiar. Since it is only a simple extension of familiar desktop applications used for videoconferencing, the setting up of the equipment does not require expert technical staff. It is also reliable, since it uses technology that is in constant use. It is also compatible with the technology many people have on their desk, enabling visiting lecturers to lecture from their office.

Disadvantages

The limitations of this technology are the low resolution and frame rate of the video and the low quality of the audio.