[yummyfajitas]

So your suggestion is to disregard all data without perfect controls? In that case, we have no evidence whatsoever that any nation outperforms any other nation.

The fact that they don't do standardized tests doesn't mean it's impossible to know whether they're doing better.

How can one possibly know this, even in principle?

If you are being intellectually honest, your answer should agree with your principle of ignoring all data unless perfect controls are used.

[CPlatypus]

"How can one possibly know this, even in principle?"

Are you seriously suggesting that standardized tests are the only way to measure school or student performance? What about non-standardized tests showing improvement within the same region or district? What about measuring achievement differences after leaving school? There are plenty of other options besides standardized tests.

In addition to cherry-picking and strawman, you've just added the the excluded middle to your list of fallacies. There are more than two options here, not just standardized tests or mere guesswork. Just because something can't be measured by one yardstick, even if it's the most accurate one (which itself is debatable in this case), doesn't mean other yardsticks won't suffice. Do you really want to turn this into a discussion about intellectual honesty? I'd relish the opportunity to cast your disreputable claims and tactics even further into oblivion.

[yummyfajitas]

Hmm. So you trust the results of non-standardized non-normed tests, even though no such tests have actually been cited.

You are unwilling to trust the results of an internationally normed and standardized test (PISA) after controlling for some but not all exogenous variables?

But nevertheless, you are willing to trust the results of the internationally normed and standardized test without controlling for any exogenous variables?

Heh, you had me going for a while. Now I realize you are trolling.