A REVOLUTIONARY scheme to improve children's learning has had to be put on hold because schools are not ready, it was announced yesterday. Director of Education Mr Dominic Wong Shing-wah said the concept of the targets and target-related assessments (TTRA) was well known and supported, but he acknowledged that its introduction would have been too rushed. About 85,000 children in Primary Four should have started the TTRA scheme, which aims to improve learning by allowing individuals to progress at their own pace, next month. But the compulsory introduction to schools has been put on indefinite hold. Professor Rosie Young Tse-tse, chairman of the Education Commission which proposed TTRA, welcomed Mr Wong's decision. But teachers said schools should introduce the scheme only when they were ready. An advisory committee is to be set up next month to propose solutions to problems highlighted by an Education Department review of the current TTRA pilot and to plan a firm timetable for implementation. Among the complaints voiced to the review team were: A need for more intensive teacher training; A need for additional manpower and equipment; Absence of concrete guidelines on how to carry out the assessments; An unrealistic timetable for implementation, particularly starting in the middle of a school year. Mr Wong said he had always been prepared to be flexible on the introduction of TTRA. ''It is a very good concept and is widely supported. With hindsight we can say the implementation was a little hasty,'' he said. ''We did not expect the amount of training to be insufficient from the schools' and teachers' point of view.'' He said implementation was likely within five years, but that depended on the recommendations of the advisory committee, which would be asked to report by November. Professor Young said it was wise to delay implementation until all the problems had been solved. ''This is something that is very new for Hongkong, and there will be teething problems. Heads are not enthusiastic about it at the moment and you have to get the support of teachers. But it is an excellent scheme.'' Mr Cheung Man-kwong, legislative councillor and president of the Hongkong Professional Teachers' Union, welcomed the postponement of TTRA. He said he hoped the teacher unions would be represented on the advisory committee, because the success of TTRA would depend on teachers and heads, not on administrators. He disagreed with Mr Wong's assertion that the new system could be introduced into classes of any size. ''TTRA is supposed to let students follow their ability one by one,'' he said. ''But if there are so many students in a class, how can a teacher teach them one by one? We will not be able to promote TTRA until there is a decrease in class sizes.''