Major reform of the 14-19 education system in Wales will only succeed if policy-makers disregard GCSEs and A-levels, according to a leading academic.
David Egan, professor of education at the University of Wales Institute, Cardiff, said that traditional examinations were barriers to large numbers of students, and more focus was needed on good-quality teaching instead.
Speaking at the Welsh launch of the major Nuffield review into 14-19 education, Professor Egan said it was "total madness" that "high-stakes assessment" still ruled in that age group when Wales had ditched external exams at other key stages.
"Do we need national assessment of students three times in three years?" he asked.
"Curriculum and assessment are important, but they are not nearly as significant as quality teaching and leadership. There's been far too little focus on this in 14-19 reform in Wales.
"We need to see an end to the GCSE and A-level as we now see them. Greater focus on learning and teaching is the key ingredient of improved student achievement."
The Nuffield review of 14-19 education in England and Wales - the largest report of its kind for 50 years - applauded Wales's "inspiring vision" and "distinctive" policies.
It suggested that England could learn lessons from some of Wales's more successful policies since devolution, such as the Welsh Baccalaureate Qualification and the 14-19 learning pathways, but said the country still compares poorly to England in terms of results.
Gary Brace, chief executive of the General Teaching Council for Wales, said the report must be useful for Wales and not only be seen as a handy comparator between the two countries.
Professor Gareth Rees of Cardiff University, one of the report's authors, said that although the Welsh education system is closer to the model advocated by the review, policy-makers and professionals could not afford to "rest on their laurels".
"Precisely because the favourable contrasts with England are so stark, there is a danger of us falling into that way of thinking," he said.
"We should be justifiably proud of the system we are developing, but that must not mean we should close our eyes to the problems that need to be tackled."
Specifically, poor attainment levels need to be addressed, said Professor Rees, and although education can play a role, it cannot compensate for social disadvantage, which is often the root cause.
Chris Tweedale, director of the children, young people and school effectiveness group at the Welsh Assembly's Department for Children, Education, Lifelong Learning and Skills (DCELLS), welcomed the report, which he called a "first-class piece of work".
Mr Tweedale said Wales has great policies, but the focus must be on implementing them and assessing their outcomes.
"We can't change society completely, but we can raise aspirations," he added.