Dullness: it's the opposite of "interest." Interest means having a stake in something, some involvement, some reason to care. Uninterested and disinterested come to mean the same thing after all!

I find Charles Wright a dull poet. I've never found a reason to be "interested" in him. I don't find his work howlingly bad; it seems to take few risks, in fact, so is unilkely to be bad.

What would constitute a risk, anyway? Writing a poem with no visual appeal, for example, like Creeley's
"Immoral Proposition." The idea of good poetry as something that can be visualized. That works in 90% of cases. That is to say, I could teach that one simple principle to someone and make him or her a better poet just by doing so. But Creeley, who loves Williams and obviously has a good visual sense, very often will write a nearly imageless poem. Why, when it would be so much easier to write "good" poems with lots of visuals? He is looking for, and finding, a more abstract language that has its own, less obvious pleasures.

So the beginning writing student, you would first show the advantage of substituting images for abstract language about "feelings." Then, once understood, show what Creeley can do even without images.

An exercise I developed for my undergraduate students: rate a poem in various dimensions, visual, linguistic, auditory, tactile, affective, intellectual. That is, how much emphasis the poet is putting in each direction (not necessarily how successful it is, but what the poet is trying to do). It can be almost an obejctive measure. It helps you to perceive poetry, say "what is it really?" For example a poet for whom sense of touch is more important than sight. That's a good thing to know. Take care of your perceptions and your "taste" will take care of itself.