Learning Visions: Instructional Designers with ID Degrees? Survey Results...
Cammy Bean has updated her ID degrees survey results. It's up to 34% of IDs having an advanced degree in instructional design--higher than it was the last time she reported, but still clearly a minority.
Creating Passionate Users: Ten Tips for New Trainers/Teachers
Kathy Sierra, from 2005, arguing that simply having taken a lot of classes doesn't make one a good teacher or trainer ("I'd make a good brain surgeon, because I've HAD brain surgery.") However, she also argues that motivated people can be self-taught.
But with that out of the way, nobody needs a PhD (or in most cases -- any degree at all) in education or learning theory to be a good teacher. Just as there are plenty of great software developers and programmers without a CompSci degree. People <i>can</i> be self-taught, and do a fabulous job, for a fraction of the cost of a formal education, but they have to be motivated and they have to appreciate why it's important.