Do we need proof of efficacy of writing with computers if everyone is writing with computers?
Often, perhaps more often than we realize, we change what we do in the humanities because of our enthusiasms, not because somebody has proved something. It is the ideas we experience as truth in our own minds, in our own convictions, that transforms our lives as teachers, not necessarily the proofs assembled under specific rules of evidence. As Thomas Kuhn has made clear, by specifying a single valid method of inquiry, a science excludes as much as it includes within its scope of inquiry.
I think that at the very least computers are helpful for writing. They allow extensive revising opportunities with much less physical effort than writing by hand requires. They allow significant research and search capabilities.
Just today I was working on a paper and though I had just yesterday read the entire book and marked important pages, I could not find the quote I needed. So I went to Amazon and searched through the “Look in this book” feature and found the page I needed for my quote. Whoo hoo for the computer!
Let me state clearly that I do not think computer use in the classroom is a fad. I took my doctoral prelims on a computer, the first to do so at my college, in 1989 I believe. I found it much easier to write, to revise, and to read what was written with a computer. (Though I did manage to lose my entire work about an hour before the test ended. Thankfully I found it again.)
I just thought it was a good question.