As others have pointed out, too many clicks per word. I am a sucker for a 'how many words do you know' quiz so I finished anyway. Overall I'm skeptical of the classifications. In broad strokes, the early words are easier and the latter words are more challenging, but the middle is pretty muddied.

Some of the words chosen are rather absurd/inappropriate: breviary (which I got wrong but felt like a vaguely religious word) was characterized as intermediate but I think it's much more obscure and less obvious than that; Hippopotomonstrosesquippedaliophobia was used as a word (I got that wrong as well) - any type of 'phobia' word is really the sort of thing a fourth grader opens up a page in the dictionary and points out, not a word that is used... ever; metamorphosis and kinetic were labeled expert, which I don't agree with (what elementary schooler doesn't learn about the metamorphosis of a caterpillar into a butterfly? what high schooler doesn't learn about kinetic energy?).

Most words were reasonably well defined in a way that most people would understand or recognize. A few words had poor definitions: lethargy ("the state of being lethargic" - obvious); complacent ("smug satisfaction with oneself" - I disagree that complacency is intrinsically smug); magnanimous ("generous toward a rival" - I disagree that a rival must be involved); gauche ("socially awkward" - this is sort of close but the given definition completely misses the idea of being tactless).

They call it scientific and give a hand-wavey formula, but they don't explain how words are stratified in the first place. If stratified sampling is a formally recognized method of doing this, it would be nice to have a link to a real reference. I think I know a lot of words, but I am skeptical of the estimate this app provided (north of 75k).

I'll contest a few of these, which I thought were good.

Breviary: this was, to me, known and not uncommon. It's widely known to Catholics, but also, if you have an interest in medieval art or books, you'd likely know it too. It was one of the main types of books before the invention of the printing press. Think of an image from an illuminated manuscript, 50% chance it's from one.

Hippopotomonstrosesquippedaliophobia: it's not that you're expected to know the whole word, but they're looking for you to recognize components of it and infer the meaning from that. I knew sesquippedalian (sometimes jokingly used in "long word" contexts) so that was easy: but phobia is also easily identifiable, and hippo, from the latin root, I knew was not as obvious as the animal, but probably something like "large" (clue: the Hippodrome). So you could, even knowing only "phobia" and being able to guess "hippo", have a good basis for your choice.

Complacent and gauche: have heard both these uses, I think that's straightforwardly correct. If this was a dictionary that would, at worst, be the 2nd or 3rd definition. No complaints.

Source: I used to place in spelling bees and could've been a contender but I didn't have the discipline to study the dictionary for hours on the weekends, which is the next level.

Yeh, it had 'kerfuffle' as one of the last words but that's very common. Yet it had Zenzizenzizenzic (which I'd never heard of but I think I guessed it right)

It really could do with a summary showing the answers you made and corrections for what you got wrong.

"Hippopotomonstrosesquippedaliophobia"

Hippopotamus does mean river horse and I was caught out by that (note the o instead of a in ...poto...). I think that word is really a joke - lol - a bit like floccinausilihilipilification, which I wont bother looking up the speling 4.

The test hardly seems adaptive (if at all) and yet it made the HN front page. That’s impressive.

69400 for me, and I knew I fucked up on ~ 5 I really did know.. or perhaps I didn't know them as well as I thought?

> what high schooler doesn't learn about kinetic energy?

95% of Americans.