In this question by Henry Flower about the placement of scrollbars, Henry asks "is there a deep study available" on the topic and offers his personal experiences and some commentary. But the question itself is "Is there a deep study available?".
However, 100% of the answers are by members offering their expert opinions.
This led me to wonder the following: should we attempt to encourage answers backed up by research, and possibly even discourage answers based on expert opinions, when the person asking the question specifically asks for proof/research/references/studies?
I could see these kinds of questions becoming a good source of information on the internet if we can start providing links to said material, but as long as we just give our opinions, technically speaking the question hasn't been answered.