Those are the only grade levels at which the NAEP is administered. https://nces.ed.gov/nationsreportcard/guides/scores_achv.aspx https://nces.ed.gov/nationsrep

Those are the only grade levels at which the NAEP is administered. https://nces.ed.gov/nationsreportcard/guides/scores_achv.aspx https://nces.ed.gov/nationsreportcard/guides/scores_achv.asp... I’d be more worried if the author stepped beyond their scope, and went from observing results to speculating without evidence about what drove the changes. It seems like enough to say “here’s a big signal that goes counter to the stories we’ve been telling ourselves, it’s worth doing some work to figure out what’s going on.”