Someone corrected my use of personas the other day and pointed out that the plural is personae.
File under reason 42.b of "Why people hate technical communicators."
It reminds me of "data."
A good sentence says "The data is clear on this."
The better sentence says "The data are clear on this" because we know that the singular is datum and data is the plural.
The best sentence says "The data is clear on this" because that's how real people talk.
Miller Williams, a former poet laureate, said he wanted to write poetry that cats and dogs could understand.
I don't know about you, but I never met a dog that could relate to personae--not even the ones named Rex.