patio11 on language learning:

"...A lot of people have vague goals like "I want to learn French" or "I want to be fluent in Japanese." There is no defensible definition of the word "fluent." Instead, you should have specific goals which test ability to complete tasks that are representative of the larger set of tasks you need to be good at to achieve metagoals which are important to you.

This is why I care relatively little about "fluency in Japanese" and quite a bit about "what percentage of commercially significant terms in my apartment lease did I understand without having to ask a Japanese speaker to explain them to me?"

That task is roughly representative of many tasks required to achieve my metagoal, which is "being a functioning adult / educated professional in Japanese society."

Now how do I measure progress? Well, I have some notion of groupings of tasks by difficulty level. The "apartment lease" task is in the same grouping and difficulty level as the "employment contract" task was or the "extract the relevant rule for recognizing SaaS revenue from the National Tax Agency's docs" was. Given roughly comparable levels of difficulty, if I start doing better on a task where previously I did poorly, then I'm progressing.

Why don't I just take Japanese tests yearly? Because my metagoal is not becoming the best Japanese test-taker there is. They are good from the perspective of many decisionmakers, since they allow decisionmakers to compare me against other people in a reproducible and cheap-at-the-margin fashion, but that doesn't get anything that I value. I don't care how I compare to Frank or Taro -- being better than Frank will not save me social embarrassment if I have to ask an accountant "Here is my... um, I don't know what the word is, but it's the piece of paper that records the historical prices I purchased by assets at and then their declining present value representing their worth diminishing over time as calculated by the straight line method. There's an accounting word I'm searching for here and I bet it is followed by the word 'schedule.' DEPRECIATION. Yep, that's the one, thanks."

https://news.ycombinator.com/item?id=9341401