alt Hacker NewsPolitics and ideologies aside, just trying to be rational....
Can someone better informed about these metrics (the NAEP specifically) comment: how exactly do we know that we're comparing the same thing each year? Is the NAEP based off answering the same questions every year? Because if it's just like "average exam result" - those can change a lot. And can in fact trend, meaning change in the same direction for several years (e.g. becoming harder, becoming easier)
Not everyone takes the same test. So you can repeat some questions on some tests year over year, or have some experimental questions that aren’t graded one year but used for establish norms for when it’s graded in future years.