In May, 2015, there were many media reports about the global school ranking published by the OECD. Although the OECD actually provided not school rankings but a table titled "Average Performance on International Student Achievement Test" in its report, many media people took it as school ranking table and reported that Asian countries topped the list. Anyway, it was a good news for the people in general in those Asian countries.
However, I wonder if those school educators should really be congratulated, because this ranking table is not directly related to the school evaluation. It was made just by amalgamating the results of international tests such as PISA and TIMSS, which are primarily designed to assess the students' academic ability, but not to evaluate schools. Therefore, for viewing this table as a global school ranking, we need the assumption that all the credit for the students' achievement should go to schools.
As I discussed before, Asian education is consisted of two sectors, which are school education and shadow education (out-of-school education). And according to the report of Asian Development Bank, all the top ranking Asian countries in that table as well as other countries see thriving business of such shadow education. Therefore, some of the credit have to be deducted from schools and transferred to it. Thus the above assumption is undermined considerably, and the table cannot necessarily be referred to as school ranking.
Although it may be difficult to determine which sector is better for improving students' basic skills in this kind of dual structure of education, it is reasonable to think that shadow education is more effective than schools, because parents in those Asian countries pay for it by their own or children's choices.
In fact, in Japan, a government survey revealed that two-thirds of parents attributed the growing role of juku (Japanese version of shadow education) to shortcomings in public education.
The world education reporters as well as policy makers seem to take it for granted that basic skills or other academic things have to be imparted only through school system, but it is a preoccupation that is not always true and probably the cause of misleading reports.
The OECD official suggested that we should learn from the world example of improvement in education. However, this preoccupation can mislead us to the wrong side, as seen in the recent example in the NY Times.
Singapore tops OECD’s global school ranking, US placed 28th
Universal Basic Skills - What Countries Stand to Gainhttp://www.oecd-ilibrary.org/education/universal-basic-skills_9789264234833-en
Shadow Education: Private Supplementary Tutoring and Its Implications for Policy Makers in Asia
Testing Time: Japan's Cramming Schools
Education - Post 2015