Snape's Dementor Essay

[potioncat]

No: HPFGUIDX 145798

In the beginning of HBP chapter 21 Ron, and several other 6th years 
are working on "a viciously difficult essay for Snape." Harry and 
Hermione have already finished it. Harry expects to get low marks 
because he disagreed with Snape over the "best way to tackle 
dementors." I was a little surprised that Harry had finished the 
essay, looks like his DADA work habits are better than his Potions 
work habits had been.

Later we hear that Seamus went to bed cursing Snape and his essay. 
Then we have the funny bit about the spell-check on Ron's quill. 
We're set up for the "Roonil Waslib" name that we'll see later. 

Hermione comments that "...we're asked how we'd deal with 
dementors..."

So, why do you think the essay is so hard? And why is Ron using the 
words "belligerent" and "augury"?  Erm, I'm glad I looked this up. 
Augury is not the same as an Augerey, which is the direction I was 
heading.

I know we discussed once before whether Snape had a different way of 
fighting Dementors than Lupin did, or if he had a different way of 
conjuring a Patronus. And of course, we won't discover whether Harry 
was right about the marks.

Potioncat, just wondering