faculty application - What is the appropriate length and specificity for a teaching statement?

A colleague and friend has been approached by another institution (a state university in the U.S.) seeking to fill a position. My friend, who is putting a package together, has asked me to review his teaching statement. Evidently, this was a good idea.

I read the statement, and, quite frankly, I wasn't too impressed. He and I are quite candid with each other, so I'm not too worried about what might otherwise be a delicate issue: me telling him how much it needs to be polished.

That said, I'll admit: I have very little experience with teaching statements (either writing them, or reading them). I'm not usually on faculty hiring committees; I don't want to give him bad advice out of ignorance.

My questions are:

1) What is an ideal length? (So far, I've narrowed it down to half a page is too little, and three pages is too much.) Would a single page be considered too thin?

2) How detailed should it be? My friend talked about different courses he has taught, even mentioning one course by its catalog number. I initially thought that generalities would be better. In other words, instead of saying something along the lines of:

Teaching styles should be adaptable, based on the student demographics in the class. For example, in my Intro to Programming course at Urbandale College, I taught had mostly freshman, but the Programming Languages course I taught at Westerville University, CSCI 352, was a more advanced course with juniors and seniors...

my gut instinct tells me it would be better to say something more general, such as:

Teaching styles should be adaptable, based on the student demographics in the class. For example, I've taught some courses with mostly freshman, and other more advanced courses with juniors and seniors...

but perhaps I'd be dishing out out some bad advice if I recommended a more general wording; maybe applicants are expected to weave such details into their teaching statements.

Answer

My answer comes from Mathematics, but probably it's quite similar.

1) 1-2 pages is pretty typical.

2) My general advice is to include details and concrete examples where possible (though course numbers are not necessary). One problem with just being general is such statements feel very generic, and lack any real content in the sense that they don't distinguish you, in the same way many political speeches turn out.