Physical environment

Desk top — Hopefully, any system that is being used on the desk top will have been designed to accommodate most of the immediate environmental prob lems. There is not the opportunity to compensate on the desk-top to the extent that is possible in a studio. Things to be aware of are:

• Camera position — this may be fixed by the system, if not, the position ac knowledged to give the greatest chance of simulating eye contact is above the screen, in the centre and as close to the screen as possible.
• Glare — This may be a problem for you in seeing the image on your screen but also may be a problem for the camera so you may need to pay atten tion to the position of the system (preferably at 90 degrees to the win dow) or to the provision of suitable blinds. The lighting itself may also provide a problem and filters to tubes may need to be fitted.
• Lighting levels — Even if the system is designed to be used on the desk top and is therefore quite tolerant of a variety of different lighting levels, there does need to be adequate light provided for the cameras to be effective.
• Audio — It is difficult to achieve good quality audio even in specialised stu dios. Depending on the conditions this can require very careful attention in a desk top situation. Under some working conditions, it may be bene ficial to use headphones if this is possible.

Roll-about — Again, roll-about systems are designed to be used in normal room environments but as in the desk-top situation, it pays to be aware of environmental considerations. If the quality is not as good as you expected, do not assume that the equipment is at fault before you have checked the environment.

Studio-based systems — If you are going to use large-scale videoconference rooms, they will need to be appropriately furbished. Most major suppliers and service providers are aware of the basic ergonomic recommendations for videoconference rooms. Some key points are listed below:

General feel

Videoconferencing rooms should be designed to fit the needs of the culture of the organisation.

Position of participants

The distance between participants and monitors should be between 4 and 6 times the vertical size of the screen. It can help if all participants are the same distance from the camera.

Seating

Adjustable seats are recommended (for height) especially when a split screen technique is used.

Table shape

There are not clear recommendations, there being advantages and disadvan tages with different shapes. Most commonly found are the semi-circular table, wedge-shaped table or a combination of both.

Decor

The general decor on walls, floors and ceilings should not use saturated colour like shiny white or black. Any limitations which make it difficult for the camera and codec to work should be avoided.

Lighting

Lighting levels should support the natural appearance of the participants and should enable them comfortably to read documents (on screen and hard copy).

Monitors

Monitors need to be carefully positioned so that participants are able to see the image of people, text and graphics clearly.(McFarlane, R.E. and Nissen, R.J. (1982). Room design and engineering for two-way videoconferencing. In: Teleconferencing and electronic communications: Applications Technology and Human Factors (ED. Parker, LA. and Olgren. C.H.))

The height of the horizontal axis should have the mean height of the speakers’ eyes. The use of big screens is recommended for graphics representa tions.

The monitors should be of dimensions which enable life-size images of the speaker to be portrayed.

Visual angle

The horizontal visual angle of the main monitors should not exceed 60 de grees. The vertical visual angle for these monitors should be between 1 and 10 degrees.

Cameras

If a spilt screen is used, 2 cameras will be necessary. Each camera will focus on half of the participants (3 max.).

Cameras should be integrated into the general decor so that the room will be like a conference room and not a television studio.

Image size

Large image size seems preferable to small image size (where possible natural size is recommended).(Velthvijsen, A (1988). Human Factors in Teleconferencing. Twelfth International Symposium on Human Factors in Telecommunications. The Hague.)

Audio quality

Attention should be paid to audio as well as video quality. The acceptance range in video quality is usually much broader than that of audio quality. Not being able to hear clearly can completely ruin a conference.

Video-Audio delays

The unidirectional end to end delay should be as low as possible and in any case not greater than 250 ms. The delay becomes noticeable above 125 ms.

Ambient noise

Assuming that the noise in the premises around the conference room is typically about 40 dB, the speech level transmitted by the room walls (and doors) should be less than 25 dB in order to ensure a high degree of privacy. An insulation of about 45 dB is therefore required assuming that the overall talking/listening levels into the rooms are around 70 dB.

Environmental conditions

Temperature and humidity levels are important. The following recommendations are given assuming the equipment is on and participants in position.

• Temperature range 20-22_ C (68-72_ F)
• Relative humidity range 40%-55%

TV-type broadcast — Attention will need to be paid to the environment of the room from which the lecture /demon stration is being broadcast. If possible, professional audio- visual expertise should be used. The environment in the room to which the broadcast is made will depend on things like the size of the audience and the equipment available.

Social environment

• Consider what clothing will be worn. Avoid garish colours and stripes/polka dots.
• Respect the chairperson if there is one. More formal video conferences (particularly studio-based) work better if there is a chairman. Sometimes the chairman will even decide which image will be seen at which stage in the proceedings. Depending on the type of communication, this can sometimes be more effective than voice switching.
• If using voice switching, activate the microphone (or release mute') before speaking and remember to close microphones (or select ‘mute') after speaking unless the system is good enough to accommodate casual noises.
• When using the remote control for cameras, do not focus only on the speaker but provide a general overview of other participants as well.
• Do not disregard the common courtesies usually used in an equivalent face to face communication
• Always bear in mind any time constraints. (Time con straints are often less flexible in videoconferences than face to face communications and this requires discipline.)
• If someone new enters one site and is introduced to the others at that site, if it is appropriate, extend the introductions to let the other sites know who has just joined in.

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