Of course scientists are aware of medians. However if you look at PISA rankings, they use the mean scores not median.
You have way too much faith in rankings you see on the internet.
> Show me a better way to compare countries when it comes to reading skills.
Median scores, mean with standard deviation, box plots. All of those are better. None are great because comparing reading scores in different languages in a meaningful way is nearly impossible.
For example, Chinese children take much longer to develop their vocabulary than American students because of the way their language is written. Because of this you can't possibly construct a test that makes an accurate comparison between Chinese and American students.
You might as well try to make a test comparing how well American schools teach welding to how how well Chinese schools teach painting.
>You know there's studies ranking countries based on diversity right? You want me to Google them for you?
And only 1 of the countries that ranks higher than the US in diversity ranks higher than us on the PISA list.
https://en.wikipedia.org/wiki/List_of_countries_ranked_by_ethnic_and_cultural_diversity_level https://en.wikipedia.org/wiki/List_of_countries_ranked_by_et...
The countries the US is unfavorably compared to nearly all appear near the bottom of that list.
It also doesn't take into account the amount of difference between cultures. For example, an African country where 20% of the people speak a different language from and don't intermarry with the dominant culture, but that have lived side by side with the dominant culture for hundreds of years will be ranked the same as a country where 20% of the people are immigrants from a country on the other side of the world.
The US has a far larger percentage of immigrants than any other country, and from far more countries.
Furthermore the US has far higher income inequality than most of the countries that outperform it.
>You just said you don't believe the study is relevant. So why do you care what it says.
It's not. I care that people are pushing PISA rankings as some kind of objective measurement of countries' education systems, and because of that politicians use them to try to push changes without understanding what the rankings actually show.
I can assure that in among academics in education PISA rankings are very controversial. Despite all your insistence about not being debatable it most definitely is.
Here's an example of some of the criticsm
--From the Times Educational Supplement
https://www.tes.com/news/school-news/breaking-news/long-read-does-pisa-really-tell-us-anything-useful-about-schools https://www.tes.com/news/school-news/breaking-news/long-read...
https://www.tes.com/news/tes-archive/tes-publication/pisa-rankings-are-utterly-wrong https://www.tes.com/news/tes-archive/tes-publication/pisa-ra...
"With greater power comes greater scrutiny. In 2013, TES revealed damning new allegations against Pisa from statistical and mathematical experts who said that what had become the world’s most influential education league tables were, in fact, “useless”, produced “meaningless” rankings and were compiled using techniques that were “utterly wrong”.
In response, the OECD admitted that “large variation in single country ranking positions is likely” because of the methods it used. For example, in 2009 the organisation said that the UK’s Pisa ranking out of a total of 74 countries was between 19th and 27th for reading, between 23rd and 31st for maths, and between 14th and 19th for science.
But this admission has made little difference to how rankings are reported in the media, and Pisa does not put the caveats centre stage. The resulting league tables are often taken as definitive statements on the quality of schools systems. And the stakes have become so high that a slip of a few positions caused by statistical variation might today spell the end of an education policy or even a minister’s career."
--From an open letter to the OECD by over 100 academics
https://www.theguardian.com/education/2014/may/06/oecd-pisa-tests-damaging-education-academics https://www.theguardian.com/education/2014/may/06/oecd-pisa-...
"Critique #1: Whereas the explicit purpose of ranking countries by average test score is to allow for inferences about the quality of national educational systems, the ranking is misleading because the samples of students in different countries have different levels of family academic resources (FAR)."
"Critique #4: The OECD has repeatedly held up Shanghai students and the Shanghai educational system as a model for the rest of the world and as representative of China, yet the sample is not representative even of the Shanghai 15-year-old population and certainly not of China. In addition, Shanghai schools systematically exclude migrant youth. These issues should have kept Shanghai scores out of any OECD comparison group and raise serious questions about the OECD’s brand as an international testing agency."
"Develop alternatives to league tables: explore more meaningful and less easily sensationalised ways of reporting assessment outcomes. For example, comparing developing countries, where 15-year-olds are regularly drafted into child labour, with first-world countries makes neither educational nor political sense and opens OECD up for charges of educational colonialism.
--From a guardian article
https://www.theguardian.com/news/2013/dec/03/pisa-methodology-education-oecd-student-performance https://www.theguardian.com/news/2013/dec/03/pisa-methodolog...
"From the outset, Pisa has been met with scepticism, criticism and even outrage, most of which has stemmed from the claim that the study's findings are arbitrary. One such voice was Dr Svein Sjøberg of the University of Oslo, who claimed that a small change in question choice or weightings could result in a big change in a country's overall rankings."
"The sheer breadth of Pisa has also raised questions about the comparability of results within it. Even those who accept it is fair to assess countries and economies alongside one another question some of the cultural factors that divide them. Joachim Wuttke, a teacher of computer science in Germany, is one such sceptic. Wuttke looked at which students failed to complete the test and which preferred to increase their speed – even at the risk of increasing their errors. He found significant differences in student behaviour that affected student performance:"
"At a more fundamental level, some have pointed to the difficulties of testing students in such a wide array of languages. If such a thing as a perfect translation exists (few would argue it does) it might still not be enough to control for students' differing interpretations of the same set of instructions."
"There is also a temptation to grab at averages from Pisa to understand the performance of a country. Doing so would obscure the vast differences that can occur regionally within a country – such an oversight can be particularly dangerous, say critics, for understanding the true academic opportunities available in a country."
"Meanwhile, countries such as Finland, a consistent top-performer in the Pisa league tables, has been accused of failing miserably on other international academic tests such as TIMSS. Why? Gabriel H Sahlgren, the author of a book on the dubiousness of the Finnish miracle claims it is “because its centralised curriculum has ignored certain concepts that are not tested in Pisa”."
https://www.washingtonpost.com/news/answer-sheet/wp/2015/04/19/pisas-potentially-dangerous-problems-and-what-to-do-about-them/?utm_term=.49bd492314f6 https://www.washingtonpost.com/news/answer-sheet/wp/2015/04/...
http://nepc.colorado.edu/newsletter/2015/10/international-test-score http://nepc.colorado.edu/newsletter/2015/10/international-te...
https://www.uv.es/RELIEVE/v22n1/RELIEVEv22n1_M15eng.pdf https://www.uv.es/RELIEVE/v22n1/RELIEVEv22n1_M15eng.pdf
>>> And only 1 of the countries that ranks higher than the US in diversity ranks higher than us on the PISA list.
Irrelevant. You and the grandparent are making an irrelevant point again and again. Why bring up diversity at all?
>>> It also doesn't take into account the amount of difference between cultures. For example ...
I already said there was going to be a "median" example... I was right about that, shocker. /s
>>> The US has a far larger percentage of immigrants than any other country, and from far more countries.
Except Canada and Switzerland and many other countries, right?
Thanks for the criticisms about PISA, never said they weren't any (see my previous comment). I asked repeatedly for alternatives instead.
The criticisms are pretty weak as well.
"In addition, Shanghai schools systematically exclude migrant youth."
If they are migrants, they're not representing the local education system now do they?
>Irrelevant. You and the grandparent are making an irrelevant point again and again. Why bring up diversity at all?
Because it's highly relevant when talking about an average value. The more heterogeneous a population is the less likely an average is to be useful.
>I already said there was going to be a "median" example... I was right about that, shocker. /s
Ranking by mean often isn't useful...shocker
>Except Canada and Switzerland and many other countries, right?
Sorry I meant large countries.
>If they are migrants, they're not representing the local education system now do they?
They're talking about long term migrants that represent about 40% of the population.
Look at Australia were 90% of 15 year olds are enrolled in school, vs. a country like Vietnam where 15 year olds routinely drop out and work.
How does that comparison make sense?
Some other examples.
In South Korea parents force their children to spend 4 or 5 hours with private tutors after school each day. South Korea performs very well on PISA league tables, but it probably says very little about the efficacy of the Korean school system vs any other country where parent don't routinely force their kids to pull double school shifts with private tutors.
Finland spends much more time teaching fractions than algebra to 15 year olds. The US outperforms them on algebra questions, but Finland outperforms on fraction questions. But PISA weighs fraction questions much higher than algebra questions.
In the US homeschooling is common. In Germany it's illegal. Home schoolers score much higher on the SAT and ACT, so in the US you're pulling 3 or 4% of the likely highest scoring students out of the pool--of course that's going to drastically affect the mean score.
We can't come up with tests that accurately compare abilities across cultures in the US. How can we possibly do it across 65 countries.
The answer is, you can't do it. Attempting to do it, failing, and publishing data that makes it look like you can is more harmful than just not publishing at all.
The critiques are numerous and come from very respected publications, organizations, and academics.
You can disagree with the critiques all you want, but you can't pretend the debate is over, and that there is some kind of settled science here.