Another way to phrase my students' dilemma is that they don't know whether to regard strange writing as ("deep") avant-garde literature or ("random") nonsense. It's a hard thing to figure out, especially if you're not much in the habit of reading poetry.
I was tickled to run into this video of the MSNBC pundit Rachel Maddow explaining dada:
Peter Bürger it's not; as Maddow admits, "art history class was a long time ago."
Maddow raises dada as a possible explanation for an incoherent John McCain ad: perhaps it's incoherent because he's trying to smash art as an institution. By identifying it as dada, we could file it in the "deep" category. Of course, Maddow is really trying to argue that it's not "deep" at all, but rather "random."
But Maddow's satire hinges on a (supposed) formal similarity. Both dada and this ad are identified as incoherent. That doesn't actually help my students tell them apart!
This is why we need better shorthands for avant-garde writing than "weird stuff."
In my dissertation I show that the mama of dada is really Nana.