For my MA paper to be accepted it had to be read by another professor in the department. They gave it to Prof Gidengil who was my undergrad Methods prof and I just love her. A lot of what she does is gender related, she's fantastic at explaining stats to a room full of math-phobic Honours students, and she wore great little ensembles. She wrote me back a page and a half of feedback, which scared the crap out of me, but talk about dedicated. (She's on leave too!)
Anyway, one of her points was that I probably meant "percentage points" rather than "percent" when talking about the difference between various results. I am so much The Fuul that I had to ask Prof Soroka what this meant.
And now I had to relook it up on Wiki to make sure I've grasped it before I write. Sigh. I can learn math, but I need things explained to me several times, and sometimes in different ways, before it sticks. I'm the person asking Dumb Questions a zillion times over. It's not that I didn't get it the first time, but it did NOT stick.
Anyway. This is a good explanation:
"In the case of interest rates, it is a common practice to state the percent change differently. If an interest rate rises from 10% to 15%, for example, it is typical to say, "The interest rate increased by 5%" — rather than by 50%, which would be correct when measured as a percentage of the initial rate (i.e., from 0.10 to 0.15 is an increase of 50%). Such ambiguity can be avoided by using the term "percentage points". In the previous example, the interest rate "increased by 5 percentage points" from 10% to 15%. If the rate then drops by 5 percentage points, it will return to the initial rate of 10%, as expected."
I am definitely going to use "percentage points" because I've always had trouble talking in real percentage, as in the above example. :-) Yikes.