tarquin wrote:
As a classically-trained musician, I know a lot about music theory. [...] Rational, intelligent wikipedians ought to be expected to recognize when someone has more expertise in a given field than they do.
The problem here is that we know a lot about a topic, but we don't necessarily know how to explain or teach the topic to those who know less, in such a way that makes them realize that they know less. There is much literature on how to teach in an effective and efficient way, and how to write useful texts. But all normal teaching assumes that the student knows he is the student and doesn't falsely believe that he is the teacher. Here we first have to establish who is the teacher and who is the student. We cannot simply tell them "you know less about this, so you are the student, and I am the teacher". That won't work. They will (perhaps correctly) believe that we are pompous and stupid. The blurring of the teacher-student relationship occurs only at the postgraduate level in our traditional education system. We cannot expect all Wikipedians to be on that level (age 25 or above in full academic careers).
It's quite a complex subject, everyone thinks they understand it, and most are mistaken.
So each article needs not only to establish a context, but also to establish how complex the topic is.
My favorite history book starts by asserting that the "ice age" was discovered in the late 19th century, i.e. it starts by telling the history of the history topic (the ice age is more recent than the telephone!). Most traditional history books would start (as does http://www.wikipedia.org/wiki/Ice_age) by telling when the glaciation happened (as if that had always been known).