Latin for "question".
This is one of the forms of writing and debate in scholastic philosophy. I had the dubious pleasure of participating in this in one of my first year modules, as a taster of 'things to come'.
Basically, in the quaestio disputata you write down a thesis, then compose and set down arguments for and against, then the question is resolved, and the questions against the thesis are answered. The thesis can, obviously, be couched in negative terms.
It works very well for simple questions, that are easily answered, but whether or not it's a means of furthering scholarship or real debate, I'm not too sure. It all too easily has a habit of getting out of control, the format encourages things to be forgotten initially, only to be brought up in debate later, and become pivotal, and with a variety of skills, you find that the less able students ask silly questions that drag the rest of the group back.
The ideal form is one probably similar to a viva, wherein one has presented a thesis, and given arguments for and against it within the body, and the examiners fire questions against it, and the student has to answer them. As a term it has variances that allow it to represent almost all forms of public debate, and even parlimentary debate is at heart a quaestio disputata.