The mother-tongue teaching policy implemented over the past decade has cost Chinese-medium school students their English abilities and their chance to study at a local university despite the fact that it does help low achievers in mastering other subjects at the beginning stage, a study conducted by the Chinese University of Hong Kong found.

The 7-year study funded by the government traced the educational progression of 37,277 students who started secondary schools in the 1998/99 and 1999/2000 academic years.

It has found that students from Chinese-medium schools outperformed those from English-medium schools in subjects including science, social studies and Chinese language at an early stage.

However, such advantage enjoyed by Chinese-medium school students diminished after the Hong Kong Certificate of Education Examination (HKCEE). Students from English-medium schools performed equally well in science and social studies subjects in the Hong Kong Advanced Level Examination (HKALE), which is necessary for entering a local university.

The study has also found that the English abilities of Chinese-medium school students lagged behind their peers in English-medium schools the whole time.

"The advantages the Chinese-medium school students had in other subjects did not offset their poor performance in English," said the university's education professor Tsang Wing-kwong.

Among the 1998/99 cohort, the ratio of Chinese-medium school students obtaining eight points in Chinese and English in the HKCEE to English-medium school students achieving the same qualifications is one to three. Among the 1999/2000 cohort, the ratio is almost one to two.

The Chinese-medium school students also enjoyed less chance to pursue higher education. The number of students from Chinese-medium schools who obtained a pass in Chinese, English, and two other advanced-level subjects in the university entrance examination was half of that from English-medium schools.

For every 100 students from the English-medium schools who got into the University of Hong Kong which required a D in English in the HKALE, only 21 and 30 students from the Chinese-medium schools managed to enter the institution in 1998/99 and 1999/2000 respectively.

Tsang said the mother-tongue teaching policy has failed to consider the demand for good English abilities in the territory and for university education.

"If gaining access to college education is one of the primary objectives of secondary education, then mother-tongue teaching has proved to be a failure in serving the best interests of the students," he said.

Only 112 secondary schools are allowed to teach junior classes in English after Hong Kong's handover under the mother-tongue policy which aims to let students learn with ease.

Tsang said it is unnecessary to insist on mother-tongue teaching given that more countries have stressed on refining English abilities in the face of globalization.

He suggested schools be given the autonomy to decide which medium of instruction to use.

Hong Kong Association of Heads of Secondary Schools chairman Michael Wong said the mother-tongue education policy has restricted Chinese-medium schools from strengthening their English-teaching.

Wong suggested all schools be allowed to teach certain subjects in English.

The Education Bureau is reviewing the policy.

A spokesman for the bureau said the number of Chinese-medium school students obtaining five passes in the HKCEE has increased by 10.6 percent from 2002 to 2007, meaning their chance to get into a university has improved.

But the spokesman added that efforts should be made to improve the English abilities of Chinese-medium school students and their competitiveness in securing a university place.