Professor Dylan Wiliam, a globally respected education academic, stated in Times Educational Supplement that:-

"International comparisons of education systems are not useful because they are plagued by missing data and the private tuition of students, and because policies cannot be simply transplanted to other countries"

"He said that, even if problems with Pisa could be overcome, he was still “sceptical” about the value of international comparisons because education policies cannot easily be transplanted to other countries."

“Even if we know why those countries are high performing, could we implement that in the UK or England? The answer is probably not."

He raised his concerns in the presence of Andrew Schleicher Head of the O.E.C.D. in a meeting of the Sutton Trust in New York. In the Guardian in 2014 it was reported that eighty-six leading educationalists from across the world wrote to Andreas Schleicher expressing their dissatisfaction with Pisa.  They stated that:-

"By emphasising a narrow range of measurable aspects of education, Pisa takes attention away from the less measurable or immeasurable educational objectives like physical, moral, civic and artistic development, thereby dangerously narrowing our collective imagination regarding what education is and ought to be about."

      Pisa ranking refer to an estimated average score which differentiated into thousandths of points. It is unclear what the difference is between the two countries or changes in attainment when the resultts are so precisely measured. It is equivalent to school nurse measuring children’s height in millimetre. The differences could not be observed.

        We are all, as human beings are not very good at assessing what is not there, and all the media are primarily interested when Pisa is announced is a countries ranking. Few know what lies behind the Pisa rankings.

        In South Korea, which is featured on the BBC 2016 Wales "School Swap South Korean Style"  programme children were learning in school, they were attending hagwons night classes up to ten o’clock at night, and they were also having private tuition help them with their maths.

      An Australian programme visited Singapore in 2020 where they have the equivalent of the old eleven plus for primary children. Binge learning was taking place there.  The parents were actively supporting their son education up eleven o'clock a night.

        The boy was asked what he would like to change most in his life. His answer was more sleep.

       The quantity of learning does not equal the quality of it. Learning is a chemical process. The amount of time that is devoted to learning each day will not be proportional to the amount of studying children do. Research illustrates that sleep is very important in consolidating learning. In both countries  issues were raised about children's  mental health.

       It appears reasonable to suggest that any could differentiate between the school influence on children's Pisa attainment of the schoool and out of school learning  they would deserve to win the Nobel Prize. There are children having private lessons in schools across the world. 

          The culture is the Far East is parents are responsible for their children’s attainment. They are highly competitive societies. In South Korea, if children fail to get into university there is no second chance. In Singapore only children who passed their version of the old 11+ could have an academic education. Both countries were implementing change.

      There is the issue of what the Pisa result really mean. Wales, Scotland, Northern Ireland and English do not have official scores and ranking. There is only an official United Kingdom score and ranking. All four unofficial Pisa country scores in the United Kingdom are different.  If they all adopted the official United Kingdom score, they all have the same score. It is non-sensical.

        If the United States is considered, they have a country national assessment where children's performance in each state is assessed. periodically. They only have one piece of ranking. There are there 73 million children in the United States. Some of their states are larger than Pisa countries. Their national assessments suggest if every state was given an individual Pisa score, then they would have some of the highest and lowest Pisa rankings in the world.  

        Pisa does not assess every child. It uses estimating and weighting to assess children who do not exist. The sample taken from each country is broadly similar, so in large countries, there are far more estimated children than in small ones. Pisa does not mark questions right or wrong. It uses complicated algorithms. It is refers to what question hoops, Pisa levels, children have reached and what hoops they should reach. The estimates come out of a black box alogrithms, which arises form myriad of repeated calculations.

    There is also the issue of languages. Language is fundamental to children’s learning. It said that the reason why Finland does well in Pisa is because the Finnish language is regular. English is one of the most difficult languages in the world to learn to read it. It takes far longer to master. The is also the issue of children no taking Pisa in their native language.

        Doctors devote around three to four months to revise for the final examination. If they retain everything they had learn in medical schools they would not need to revise for it. There is the issue of whether Far East children skills are more primed that Western children. Iuan sitting in his desk in South Korean desk did not appear to be confortable do a half Welsh G.C.S.E. paper, he did explain he had an A Star in his real G.C.S.E. 

          Professional David Reynolds, educationalist, stated in research book where he referred to maths teaching America to assertain best teaching practice not the Far East, that despite the doom and gloom about Western education children suceeded in our universities. Wales has a lot of social deprivation. Welsh education is around the Pisa average. It not an educational disaster.