'Everybody there seemed to be indulged in some sort of secret work. It was very different from other offices as the staff rarely chatted or made any noise,' he said.

He soon realised that all that 'secretiveness' was necessary in view of the huge amount of confidential exam documents the authority had to handle.

But the confidential and technical nature of the HKEAA's task has not freed it from external criticism. The past few years have been a stormy time for the organisation.

Fingers were pointed at recurrent mistakes in exam papers, leaked questions, lost scripts and low morale.

The chairman's actions were listed among the many 'crimes' committed at the HKEAA in an anonymous fax sent to all newsrooms last year. He was described as the staff's 'focus of anger'.

Looking back, Chow, who will officially retire from his post tomorrow, told the South China Morning Post he had never felt under pressure from the various controversies. He was confident in the professionalism of his staff. Criticism, like human error, could never be completely avoided.

'No matter what we do, some people will not be happy and they will criticise,' he said. 'Examination is always the target of criticism because people find it difficult to blame teachers and schools, which are really the cause of students' poor results.'

Chow believes the anonymous fax was the result of the sacking of staff held responsible for errors in exam papers.

'The public called for more accountability and would not stop probing if they did not see blood. But after laying off a number of officers in response to their call, we made a small group of staff unhappy. Then we were attacked for low staff morale,' he said.

The engineer, whose wife is Liberal legislator Selina Chow Liang Shuk-yee, may even have survived harder times when he served as member of the advisory boards of the hospital and housing authorities in the 1990s.

Chow resigned from his post in the Housing Authority amid fierce criticism that his engineering firm had produced substandard piling on authority sites.

Before he became the HKEAA's council chairman he had also helped manage the Polytechnic's transition to university status.

In 1997, an officer at the authority was caught passing photocopies of confidential papers to his son, a candidate of the Hong Kong Certificate of Education Examination (HKCEE) that year. The credibility of the authority was attacked. But Chow argued the incident only helped to prove that its security system was sophisticated enough to detect flaws and misconduct.

'Our system requires that staff declare whether they have any close relatives taking exams each year and that markers should alert us if they find any irregularities in the answer scripts. We were able to detect the leak primarily because of these regulations,' he said.

Two of the teachers who marked two of the student's exam papers alerted the authority when they noticed that his answers were nearly the same as the model answers. The authority found the same problem when they studied his answer scripts in other subjects, and eventually found that his father was the man who held the key to the safe that kept that year's HKCEE papers.

Chow said the public had often overlooked the HKEAA's achievements.

He has been a vocal proponent of the organisation taking leadership role in assessment issues in the southeast Asian region.

'It is by no means a simple task to develop internationally-recognised public exams.

'The mainland does not have them and even advanced Asian countries like Singapore use overseas exams as their public exams,' he said.

Compared with similar organisations in other countries, the authority's 'blunders' were of a very minor nature. But they were often magnified in the eyes of the public, he said.

The chairman agreed with the consultant report's recommendation to expand the role of HKEAA to cover research and the formulation of assessment policy.

The authority should also develop closer ties with the Education and Manpower Bureau's Curriculum Development Council to ensure that public exams were in line with the education reforms.

With its expertise, the organisation would contribute significantly to the debate on the number and format of public exams to be adopted after secondary school education changed from seven to six years, he added.

Chow has also been determined not to allow politics to get in the way. 'Education covers three main areas: teachers, resources, and assessment. The first two can naturally be very political as they involve money and manpower. But examinations need not and should not be political.

'We cannot serve any political purposes by manipulating statistics or being evasive,' he said.

The council chairman, who was independent and did not receive pay from the HKEAA, was in the best position to tackle politics, Chow said.

'The secretary general Choi Chee-cheong and his team should be allowed to focus their energy in the technical aspect of exams.'

Chow became the first council chairman to represent the HKEAA in Legislative Council meetings two years ago when he went with Choi to answer legislators' queries on the mistakes found in exam papers.

When asked by legislators and the media whether they could guarantee public exam questions would be free of mistakes, Chow answered 'no' and said he could only guarantee that mistakes would continue to appear. 'How could anyone expect Choi to answer such a question? The HKEAA would be in trouble whether he said 'yes' or 'no',' Chow said. 'I was accused of being arrogant and Cheung Man-kwong criticised me for being irresponsible. But I think that I would be irresponsible had I promised that there would not be more mistakes.'

Chow expected that the role of his successor, Irving Koo Yee-yin, a member of the Education Commission and former chairman of the Quality Education Fund Steering Committee, in de-politicising the operation of public exams would be increasingly important.

In a report issued in May on defining the future role of the HKEAA, the self-financing organisation was criticised for its bulky manpower structure and poor financial management. It ran a deficit of about $10 million last year.

Having frozen public examination fees for six consecutive years while staff salaries kept rising, the authority said it was in a difficult position to generate income.

Chow said it would need to consider cutting the number of exam subjects to save costs, which would inevitably touch on a highly political area. 'We have to focus our energy or even put more resources into the core subjects. Others, such as music or woodwork, could perhaps be replaced by well-established overseas exams or school assessment.

'But schools might stop offering the subjects if we decided not to run their exams. Cheung Man-kwong [as president of Hong Kong Professional Teachers' Union and legislator representing the education constituency] would worry as some teachers would be forced out of jobs as a result. That's the time when the council chairman has to step in to deal with the politics,' he said.

Another achievement of Chow's is the increase in transparency of the HKEAA.

A communication division was set up for the first time last year to raise public awareness of its role and improve staff relations. 'Before, I never knew all the technicalities involved to ensure that grading could be done in the fairest manner possible.

'Also I did not know that the HKEAA delivers exam papers to candidates in prisons and hospitals. Being the chairman broadened my perspective,' he said.