There are reports every year that compare countries and indicate that some countries are "behind" or "ahead" in math or science and other skills. Think about if completely different tests with a completely different norming sample can be compared and found to be valid. If we are taking a different test, can it be perfectly compared? What about language differences? What about the curriculum? Were they taught the same or even in the same year? I don't buy it personally. What are your thoughts on this?