That makes absolutely no sense. Shown Their Work makes it sound like someone is showing the creator themselves the work that they made instead of the creator showing other people. If it you are correct about this requiring past tense then it would still make more sense to have it be Showed Their Work. Plus, Showing Their Work has both present and past tense qualities to it because a person is still showing their work to people throughout the ages, like, Socrates is still showing his brilliance to people even after his death though the recorded things he did and said.
And thank you for pointing out my spelling error, I always end up screwing up the spelling of grammar.
I am a man of many words, I just choose not to use them.
It's not "showing their work" as in showing the work (of media) to viewers; it's having "shown their work" in the same sense as when you have to "show your work" when solving a math problem.
The author showed their work when writing the book, and now they're done writing it. If you read the book now, you can tell that they have really shown their work.
The past participle sounds perfectly grammatical to me.
Showing only works in the past sense if it's something that started in the past and is an ongoing thing. For Shown Their Work it's a discrete instance that happened once in the past.
edited 24th Apr '11 9:06:03 AM by shimaspawn
Reality is that, which when you stop believing in it, doesn't go away. -Philip K. Dick

May I ask why a trope is called Shown Their Work when the description obviously indicates it should be Show ING Their Work? Is there a particular reason it was named the way it is that I'm unaware of? I know it sounds like I'm just complaining but it's really been bothering me.
I am a man of many words, I just choose not to use them.