IndigoBlue:
The psychos are guys (I've never met a woman psycho in scuba) who want to push you around.
That's one of the strangest statements I've ever read on this board ... gender has NOTHING to do with whether an instructor is good or bad, or even suitable for an individual student.
Good instructors and bad instructors come in both genders. The only thing that should be influenced by gender is your comfort level ... a good instructor will (at least at OW level) have to be right up in your face at times, and some people are not comfortable having an instructor of one gender or the other that up-close and personal.
I do agree that every student should meet and talk with their instructor prior to taking the class.
Get a feel for how experienced the instructor is ... both as an instructor and a diver. Good instructors dive often ... and outside the class environment ... to maintain some level of context around what they're teaching.
Ask what kind of classes the instructor has taken recently ... a popular dive magazine says it best "A Good Diver is Always Learning" ... that applies especially to instructors. Those who stop taking classes after reaching instructor level often become hide-bound in the ritual of doing things the same way all the time ... and lose the ability to adapt a class to fit your needs and learning style.
Ask about schedule, curriculum, and expectations. A good instructor will be one who expects you to put some effort outside the classroom reading and learning the text material ... so they can spend time inside the classroom answering your questions and teaching you things that aren't in the textbook, rather than simply rehashing the stuff you're supposed to read. A good instructor is one who can tell you in advance what to expect from the class, the pool, and the open water sessions, and who has a prepared outline of what will be covered.
Most importantly, make sure you can walk away from the interview feeling like you can enjoy spending time in this person's class. Scuba diving is a recreational activity ... the whole point is to have fun! If an instructor takes it too seriously, you may find yourself struggling without appropriate support ... you'll be putting pressure on yourself and not having much fun. That really inhibits the learning process.
Do, by all means, interview any instructor about these things. If you end the interview with any reservations about this person at all, find someone else to teach you. Having a good instructor is far more important than the agency or shop you choose. It will often be one of the largest deciding factors in terms of whether or not you decide to continue diving after you get your C-card.
... Bob (Grateful Diver)