He was once memorably described by Michael Gove as one of the two most important people in world education, but German statistician Andreas Schleicher is still not exactly a household name.
He is best known among teachers for founding the Programme for International Student Assessment (Pisa), a global study used to rank countries by their students' performance in reading, maths and science every three years.
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Hundreds of thousands of 15-year-olds around the world complete the tests in each cycle, after which they receive a score in the three main subject areas. These scores are then used to compile an international ranking, which allows nations to compare their performance with fellow participants across the globe.
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Mr Schleicher's official title is director for education and skills and special adviser on education policy to the secretary-general at the Organisation for Economic Cooperation and Development (OECD).
In addition to running the Pisa tests, this makes him responsible for the OECD Teaching and Learning International Survey (Talis), the OECD Survey of Adult Skills (Piaac), and the development and analysis of benchmarks on the performance of education systems (Ines).
Mr Schleicher is generally considered to have a fairly progressive attitude towards education policy. However, he has been known to favour traditional approaches.
For example, he recently gave a glowing report to a secondary dubbed the UK's "strictest school".
In a blog about Michaela Community School, Mr Schleicher presented the North London secondary – which has attracted controversy for an uncompromising approach to discipline – as an example of "teacher-directed instruction".
However, the Pisa chief said he would not want his own children to go to the Wembley school, admitting he had "trouble" with its silent-corridors policy.
Michaela founder and head Katharine Birbalsingh told Tes that a “real connection” was made with Mr Schleicher and that she was surprised to find out they agreed on most education topics.
“It’s interesting because I have always imagined him to be quite a progressive, and yet he and I agreed on most things – nearly 100 per cent," she said. "We just agreed on and connected in terms of our beliefs of what is right in education."
A former physics student, who received a master's degree in maths and statistics from Deakin University in Australia, Mr Schleicher is a man of many talents – including fluency in four languages: German, English, Italian and French.
He has won a number of awards, including the Theodor Heuss prize, awarded in the name of the first president of the Federal Republic of Germany for “exemplary democratic engagement”.
What has Schleicher said about the UK?
- Making teaching “intellectually attractive” in England could be a bigger challenge than solving the teacher pay problem.
- A “focus on compliance” in England and beyond is driving innovative teachers from the profession.
- Coding (which is part of the English national curriculum) will be as irrelevant as trigonometry one day and more focus should be placed on teaching children tools that will benefit them in the future.
- He likes the look of the new Ofsted inspection framework – "putting greater emphasis" on the curriculum could allow inspectors "to value work of teachers that does not feature in exam results".
- England's schools system should put a greater premium on skills because “Google knows everything”.