The new director of London’s Institute of Education is wrong (“When pupil assessment becomes a market”, August 27). The challenge to policy-makers is not the marketisation of assessment but its bureaucratisation by the state in pursuit of ever more precision and exact comparability.

Of course we have a “business model” - the schools and colleges that choose our specifications expect the business virtues of efficiency, customer focus and quality assurance. But this is not the same as being a “commercial organisation running school examinations, highly regulated but concerned with market share and profitability”.

Cambridge University, through the department Cambridge Assessment, owns and runs three exam boards - OCR (Oxford Cambridge and RSA Examinations), University of Cambridge International Examinations, and the UK’s largest provider of English language qualifications, University of Cambridge English for Speakers of Other Languages. All are not-for-profit organisations.

Underpinning everything we do is an education mission first given voice 150 years ago, now expressed as: “We strive for continuous improvement of assessment systems and methodologies around the world to guarantee learners everywhere access to the benefits of their education.” It is, therefore, no accident that OCR’s “tag line” is “recognising achievement”.

Bene’t Steinberg, Group director, public affairs, Cambridge Assessment, Cambridge.