**Fifty Years of Research without Improving Mathematics Education**

An academic essay, February 2017

Within education, mathematics is in the front. Consequently, research has grown rapidly for fifty years to solve its many learning problems. The lack of success is shown by the PISA studies organised by the Organisation for Economic Co-operation and Development, OECD, showing a low level and a continuing decline in many countries. Thus, to help the former model country Sweden, OECD wrote a critical 2015 report ‘Improving Schools in Sweden, an OECD Perspective’: “PISA 2012, however, showed a stark decline in the performance of 15-year-old students in all three core subjects (reading, mathematics and science) during the last decade, with more than one out of four students not even achieving the baseline level 2 in mathematics at which students begin to demonstrate competencies to actively participate in life.”

At the CERME 10 congress in February 2017 a plenary session asked: What are the solid findings in mathematics education research? To me, the short answer is “Only one: to improve, mathematics education should ask, not what to do, but what to do differently.” Thus, to be successful, research should not study problems but look for hidden differences that might make a difference.