Considering this question - Explain Big O notation in your words, are questions in this form considered constructive ? There are quality answers, but in the end, everyone has their own words to describe something. Questions like this have a good chance to end up with a plethora of different answers that basically tell the same thing. Would there be a way to improve this kind of question ?
That sounds like it could be a homework question!
Actually on reading it now it certainly reads like a homework/interview question.
I think you've identified the problem with this type of question in that it will end up with a "plethora of answers" each pretty much as valid as the next. In addition there doesn't seem to be a real problem to be solved here.
I've now closed that question. If you have any others flag it for moderator attention - or better still cast a close vote yourself (assuming you have enough rep).
IMO it's condescending form of question. Whose words would you use if not your own? Are you a plagiarizer? An android? Or maybe they want you to make up something ridiculous?
I can't remember the last time I was asked such a question, but if anyone did ask me one, I'd chafe at it.