Regrettably. My med student samples were tiny, and a decade ago, but the best any of them managed for "how big is a (human) red blood cell?", with quite a bit

Regrettably. My med student samples were tiny, and a decade ago, but the best any of them managed for "how big is a (human) red blood cell?", with quite a bit of struggling (to for instance, remember the scale bar on some histology slides), was "really really small". Some, even when given the answer (in micrometers), didn't believe it. :/ I've continued to play the Sun color game with Harvard Center for Astrophysics students over the years. "A five-year old comes up to you and says, "I'm told the Sun is a big hot ball! Yay! What color is the ball? I really care about the color of balls - I'm five." What color is the Sun?" Adding "viewed from outside the atmosphere" as needed. And rejecting answers like "6500K" with "Five-year old!". Now CfA, in addition to being a first-tier astronomy research center, is also a leader in astronomy education research. And of the few students who get it right, about half (but small N) learned it in a seminar on common misconceptions in astronomy education, rather than from their own atypically successful and extensive education in astronomy. A sometimes follow-up question of "what color is sunlight?" often triggers something like an "oh, wait, that doesn't make sense, does it". Suggesting two bits of incompatible knowledge, bumping together for the first time. These examples were selected for drama. But the failure modes they illustrate seem widespread. A failure to develop a sense of scale, and a rough quantitative feel for reasonable values in one's field. And a failure to integrate knowledge, with misconceptions persisting far beyond introductory courses. The software one-liner is "if it isn't tested, it doesn't work". And current testing... has poor coverage over the set of skills one might hope for all students. On the one hand, these failures have been remarked upon for decades. On the other hand, as concept inventories spread across fields, a common pattern is "I'm sorry to waste your time taking something so basic as this new concept inventory" followed by "oh bleep, I had no idea". Which is perhaps a metaphor for the bigger picture. It seems we sort of know it's a disaster, but that hasn't quite sunk in yet. Or something. The instructor of a bio lab course saying the thing they most wish their incoming students had, was a firmer grasp of central dogma... and this in a second (or third?) year course, mostly bio and pre-med majors, at a first-tier department and university. When they've likely seen it, repeatedly, since primary school. And yet how many pre-college biology educators view themselves being profoundly unsuccessful?