There are certain types of questions you get asked a lot when you are the chief executive of the qualifications regulator Ofqual. As today is officially my last day in the job, I can answer them pretty bluntly.

“Are A-levels and GCSEs getting easier?” I don’t believe that they are - although I do acknowledge the evidence that teachers and candidates are now much better drilled in preparing for them.

“Is level 3 hair and beauty really as difficult as A-level maths?” Frankly, I don’t care about this kind of extreme comparison, and neither do university maths departments, nor the employers of apprentice hairdressers and beauticians. The important thing is that exams and qualifications should be fit for purpose - they should be demanding, assess what they are supposed to, support the progression that they claim to, and reinforce the best teaching and learning.

Ofqual has played a key role in addressing questions about qualifications, and many others. I am proud of much of the work done by it, and by its predecessor sections of the Qualifications and Curriculum Authority (QCA), which I joined as its first director of regulation and standards in 2005.

I believe Ofqual has proven there is a need for an independent qualifications regulator. That need is stronger than ever now, at a time when learners, teachers and lecturers are entering a further period of radical change.

Qualifications used by schools and colleges are by no means a perfect market. Teachers and lecturers need a regulator to make sure that standards are maintained, that marks and grades are fair, that malpractice is rooted out, that new qualifications are properly prepared for and that learners get a fair deal.

At Ofqual, we have not been afraid to tackle some taboo subjects. In 2008 we launched a programme of published work on the reliability of the marks given by examiners - a subject which for too long had been kept in the closet. We have also put a lot of resources into combating the malpractice of awarding qualifications that can be used to count towards immigration visas, causing vulnerable students to be exploited and the public put at risk. We have recruited high-quality staff who understand assessment and regulation, and we have good links with assessment experts in this country and across the world.

We are a demanding regulator when we need to be. Last year, when the first of the new A-levels and new A* grades were awarded, we made sure that the results were fair and consistent with previous years and avoided a repeat of the turmoil of 2002. We have also reported on the inadequacies of GCSE science qualifications and insisted that their replacements meet our requirements before we accredit them.

But while we have been demanding, when necessary, with the bodies that award qualifications the thrust of the act that officially formed Ofqual two years ago was that those organisations had to be held accountable for controlling their own quality and efficiency. Our job at Ofqual has been to make sure they do just that - not to do their jobs for them.

While we may have been critical at times, most teachers who have worked as examiners or observed some of the processes run by the awarding organisations have been impressed by what they have seen. There is a strong educational ethic in the awarding industry in this country, whether in the private or the public sector.

To teachers and lecturers I would say: don’t believe all you read in the papers about qualifications. Look at the evidence for yourself. Some high-quality qualifications, particularly vocational ones, are too often written off unseen. Secondly, be a demanding customer of the awarding organisations. If their services aren’t right for you, tell them. Use their appeals processes if you need to. If you’re not satisfied with their responses, tell Ofqual. Thirdly, join us in shaming out of the system shady practice involving the wrong kind of help to nudge students’ grades upwards. I am fully aware of the tensions and temptations from high-stakes accountability systems, but professionalism means assessing validly and fairly.

Lastly, the more the profession can encourage teachers and lecturers to deepen their understanding and expertise in assessment the better. Consider a spell as an examiner with one of the awarding organisations or see what the Chartered Institute of Educational Assessors offers.

I am optimistic about the future of Ofqual. The decision to create it may have been made under the last Labour education secretary, Ed Balls. But I believe the coalition Government has recognised the value of independent organisations which can take impartial decisions on complex technical issues - indeed, one of its very first acts was to create the Office for Budget Responsibility. Education ministers have told us they want Ofqual to be stronger and to continue to be an assertive defender of standards.

One of the important questions that Ofqual, teachers and awarding bodies will have to consider is: what will qualifications look like in the future? My generation and the next have a lot to learn from today’s pupils about the centrality of technology. They use IT as their natural medium. Yet we are even now accrediting new GCSEs, due to run for several years, still taken largely on paper. This cannot go on. Our school exams are running the risk of becoming invalid, as the medium of pen and ink increasingly differs from the way in which young people learn.

Isabel Nisbet is the outgoing chief executive of Ofqual.