A more complete description of the question
As the question suggests, I'm wondering if anyone could share the criteria as well as maybe heuristics or questions they use for deciding whether to take on a doctoral candidate. What really matters? What markers do you look for to tell you whether a person could be successful and a good investment of your time?
I'm a full-time Prof in a University-based Business School in the UK. Our PhD programme attracts a) lots of people in general; and b) lots of "post-experience" candidates (i.e., mid- to senior managers in their 30s and 40s). Although there is a structured way to inquire about PhD opportunities, the faculty are also flooded with random applications e-mailed to them directly from various candidates around the world. As usual with the PhD as a degree, very few people understand what this is all about and what they would be letting themselves in for. We have had a number of stellar graduates, but a lot of people struggle and suffer unnecessarily. The problem is, it's very difficult to estimate in advance which category a particular applicant belongs to (except the obvious cases, of course). So I'm wondering if anyone can share what they do to try and estimate a person's chances for success in a PhD programme - criteria, process, or anything else.