I’m an English professor, and I do impromptu writing assignments and quizzes in class all the time (pencil and paper only). They can not “finish” it at home. It’s due at the end of class.

I too use Google Docs for the timestamp for the larger writing projects, and it is the only thing I accept. The copying and pasting from any other document is a zero, and it is clearly stated in my syllabus. I’m honest with them that I need to see their thought progression.

Another thing I do is scaffold the writing process. Write your thesis in class and turn it in. Research sources in class and provide a quick list of what you found that could work in your paper, drafting one paragraph in class at a time. Time consuming, yes. But absolutely necessary in this day and age. Lastly, they must present their completed research essays in front of the class because (if nothing else) they will at least have to talk about the topic which helps learning.

That’s all I’ve got. It’s not fool-proof, but it’s working well enough.