The number of students participating in the sub-degree courses, called associate degree (AD) courses, has risen almost tenfold over the past decade, from 3,732 in 2001 to 31,093 last year. Education reform initiated in 2000 called for diversified pathways in higher education, and the programmes were introduced the following year, with the goal of doubling the percentage - to 60 per cent - of school leavers with access to higher education within a decade.

It supported the establishment of more community colleges to provide an alternative route to further education, as well as a variety of learning opportunities to help students acquire skills and qualifications that would make them more employable.

Offered by private institutions and schools of continuing education, the number of AD programmes has increased in the past decade from 46 in 2003 to 140 last year.

Tang, who is studying language and culture at the Polytechnic University's Hong Kong Community College, hopes he can eventually work towards a full degree at a local institution. "If I don't get accepted I will have to take the IELTS exam and study abroad," he says. "Deep down, I don't feel good because many of my friends have gone on to university."

Tang was among the 28,418 candidates in this year's Hong Kong Diploma of Secondary Education examination who met the minimum university entrance requirements but was denied a place at a publicly funded university. The government imposes a quota of about 15,000 for first-year degree places.

Compounding the problem for students like Tang is the rising cost of AD courses, which now set students back between HK$55,000 and HK$60,000 a year. That's up from about HK$45,000 a few years ago, which is slightly higher than the tuition fee of publicly funded universities.

Another problem is that students doing sub-degrees must get exceptionally high grades to get a place at university. The limited supply of places has fuelled frustration among many.

Although the increase in the number of AD programmes has succeeded in meeting the 60 per cent target set out in the reform initiative, there have been lingering concerns about job prospects. In response, the government has made AD graduates eligible for certain civil service jobs, such as the police force and immigration service.

The government has also pledged to double the quota of university places reserved for sub-degree graduates to 4,000 by 2015 at the latest, but that falls far short of demand, particularly as an increasing number of students plan to go to university.

Simon Wong Chi-hon, dean of continuing education at Baptist University, notes that the AD sector has over expanded in the past decade and some operators have placed quantity over quality. "It was a rush to reach the 60 per cent figure in 10 years," he says.

Last year, the two colleges of Lingnan University were found to have over-enrolled 2,000 students, leading to a teacher-student ratio of 1:200 in some classes. The head of the colleges subsequently resigned.

Wong believes the time has come for consolidation, with smaller providers closing down. At least one course provider, Sacred Heart Canossian College of Commerce, has already announced it will cease operations next year.

"There should be tighter controls on institutions, such as the size of the school campus, number of books in the library, sports facilities and [the quality of] teachers," he says.

When the government originally sought views from educators on diversifying study pathways, it was understood there would be a clear differentiation between AD and higher diploma courses. The latter would be more vocationally oriented, for those planning to enter the workforce upon graduation, while AD courses would prepare students for further academic studies.

"Broadly speaking, AD graduates are not expected to start work right after completing their courses. The programmes are to help them explore their interests," Wong says. "Now it's so messy that even higher diploma graduates from the Institute of Vocational Education want to move on to degree study. Everyone wants a degree."

Overseas universities have jumped on the bandwagon by offering top-up degree courses for graduates either independently or in collaboration with local institutions.

But some programmes are of dubious quality and can be completed in as short a time as eight months, Wong says.

"Before they start ruining the reputation of Hong Kong's tertiary education, the government should introduce more stringent controls," he says.

Since 2005, the government has further privatised the sub-degree sector, leaving the vast majority of its programmes to finance themselves. This has been a big contributor to the steep rise in course fees, with some private universities and degree-granting institutions charging anywhere from HK$60,000 to HK$100,000 a year.

John Malpas, president of Centennial College, which is run by the continuing education arm of University of Hong Kong, says the higher education system still needs to be more diverse in order to cater to the differing needs of students.

"If you want a high participation rate in post-secondary school education, in the 60 per cent sort of range like in the United States, you need a spectrum of institutions that cater to all kinds of people, from vocational schools up to research universities. When I say up to, I don't put one on top of the others," he says.

"A more diversified learning environment can be achieved by internationalising the current system."