Relationship between yield and 'quality'?

I'm wondering how you guys have found, in your experience, how yield related to quality of the buds?

Do high yields always accompany high thc concentrations, or vice versa?

Could a plant that is producing below it's 'expected' yield still have high thc concentration?

I do realize a lot is determined in curing/drying, but as a general rule, what have you found to be the case?

thanks