A video conferencing system must be interactive. This depends firstly on its technical design and secondly on how the system is used in practice. Lecturing via interactive video is a challenge and requires new teaching techniques to be developed if the medium is to be used to its best advantage. In this area it may be necessary to consider that all lecturing staff should undergo some level of media training.
It is wrong to assume that video conferencing is the same as lecturing, the technology is often unfamiliar to new users and in some case may be perceived as threatening so consideration must be given to training new users of the system. The style of presentation when using a video conferencing system is often different from a straightforward lecture so the lecturer must give some thought to changing his or her style. For example the screen format is virtually identical to A4 landscape so it makes sense to produce diagrams in this format rather than the more normal portrait format.
The booking and switching system which operates a video conferncing network should preferably be fully automatic with the ability to insert bookings up to a year in advance. This has the dual benefits of not requiring operator intervention and allows bookings to be made for times when staff would not normally be available. Some form of remote switching for multi site conferences should also be provided so that the person speaking can be seen at all the sites. This can be automatic as when using an MCU or manual as provided by LIVE-NETs lnchair program.
Ideally rooms used for video conferencing should be reserved for this purpose. If this is done then proper lighting can be installed which does not shine on the video monitors and is the correct colour temperature. The lighting on the faces of lecturers is very important. The ability to change camera views and close up from time to time adds interest to the viewing. A sole use room also has the benefit that equipment once properly installed and adjusted can be left in place and doesn't require setting up at the start of each new session.
Whilst it is possible to use a single fixed camera for a simple lecture far better results can be obtained if multiple cameras are used or the camera can be remotely controlled by the lecturer (pan/tilt and zoom). For meetings involving more than perhaps two or three people it is convenient to have multiple remotely controlled cameras focused on different people within the group.
It is also important that lecturers practice their delivery style and play it back to themselves to control bad mannerisms.
Facilities available at lecturing site should at the very least include an overhead camera (OHC) with remotely controlled zoom and focus (if not automatic) and ideally a slide/video converter and a video tape player. An OHC is far more flexible than an overhead projector, it can be used for normal paper as well as OHP transparencies and also for samples or artifacts.
Changing from point to point conferences to multi site conferences can cause problems especially with sound and the number of video channels available at each site. The use of frequency shifters or echo cancellers can be used to alleviate if not eliminate sound problems. Quad splits can be used to multiplex four video pictures into one if there are problems with video channel capacity. There is a loss of resolution when using a quad but in practice this has been found to be acceptable.
It is vital that consideration is given to the provision of technical support to maintain the highest standards of video and audio performance of the equipment used. A good picture cannot be produced from low quality or badly performing equipment.
In summary due to audio feedback, echoing and the necessity of adjusting volume levels far more technical difficulties occur with the audio side of a video conferencing system than the video side.
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