How I reverse-engineered Google Docs to play back keystrokes (2014) (opens in new tab)

It falls apart if someone makes the document in any other tool and then pastes it on gDocs.

Unless you make it a requirement to do the entire thing on that platform...

I was thinking along the same lines. One of the ways I saw paid essays work is that someone would buy the item and then tweak the phrasing of sentences and choice of words to make it a little more unique and tune it for the target level. It tends to obfuscate the plagiarism and makes it fit the style of the purchaser.

This tool even blows that out of the water.

I wonder how long before some groups recommend/require something like this to provide evidence of originality.

Not sure about that. You assume everybody will be happy to work in GoogleDocs to write their assignment. But that's not true. If you are a commuting student you probably want to write it in an offline tool (even the notepad is fine). Also, sometimes, especially if you need to be creative, to plain old paper are a much better tool to write the first draft. Finally, I like to use a spellchecker a little bit better than the one provided by Google Docs, so I will probably run the text in it and then copy back to Google Docs. Never in my flow I cheated (unless using a spellchecker is cheating that could be true for an English class). But it will be very difficult for me to prove it because you assume cheating is using a different tool from the one you try to force me. That's not fair!

Copy and Paste probably a terrible signal of plagiarism in the modern writing workflow -- which involves tons of editing, multiple documents, and more legitimate use cases for it than illegitimate.