WHEN the lecturer appeared on the television screen, the students gathered at Hongkong Telecom CSL's conference room listened attentively as she might require instant feedback, even though she was teaching them miles away from the city of Ballarat in Victoria, Australia. This was Hongkong's first-ever academic ''Video-conferencing''. It took place recently during which some 20 students from Caritas Hongkong Adult and Higher Education Service received a long-distance lecture from Dr J McGilp, a professor at Australian Catholic University (ACU). Video-conferencing is instant audio-video transmission via optic fibre cables. The service is provided by VideoNet from Hongkong Telecom CSL. The students, mostly professionals from different sectors, are in a graduate Diploma of Administration programme offered by ACU and locally administered by Caritas. Dr Deirdre Duncan, a visiting ACU associate professor who co-ordinated the lecture, said: ''This medium brings a wider range of course experts to Hongkong. ACU uses video-conferencing for distance education because it has eight campuses spanning thousands of miles on the Eastern seaboard. It seems natural for us to extend this service to Hongkong as well.'' Although the service is costly, Dr Duncan said it reduced travel and accommodation expenses from visits made by overseas lecturers. Such technology has been used mainly in business communications in Hongkong, according to Mr Denis Chen Poonis, VideoNet Customer Service Executive. Although the idea has yet to be introduced in local universities, Mr Chen Poonis said the service could be made available for a larger audience with a bigger screen. He said, however, successful transmission often depended on good co-ordination between local and foreign parties. One of the students, Mr George Hung, a computer audit, liked the interactive opportunities offered by the system but discovered some drawbacks. ''There have been occasional lapses in transmission, and sometimes, the lecture notes and graphics do not appear clearly on the small screen.'' Linda O'Donnell, another student and the head of upper classes in an international school, said: ''Video-conferencing is an interesting concept. Although communication is disrupted at times, the technicians are handling it better and better.'' Most of the other students appreciated the concentration of academic expertise such technology gives. Mr Hung Siu-po, Caritas programme administrator, said the centre would try to arrange more such meetings during the course. ''Hongkong's tertiary education is advancing and it will need more overseas expertise. Video-conferencing may become more popular soon.''