To train people to become researchers. If the definition of what a researcher is changes over time (due to AI or otherwise), then the nature of the PhD will also change over time.
I would say to push frontier of human knowledge forwards. Its not a high school anymore where you learn to learn. PhD is already a place where you should deliver value. (By "value" i don't mean commercial product)
> I would say to push frontier of human knowledge forwards.
Not sure if this is what you meant, but to be clear: pushing human knowledge forward is a practical prerequisite of a PhD (given it's pretty hard to convince people you're adequately trained to do such a thing without actually demonstrating it), but it's not the value of the PhD itself. The value is producing a researcher -- that is, someone who has the skills to continue accomplishing this in the future.
The difference is that if you happen to expand human knowledge by a stroke of dumb luck (or smart AI...) without actually having acquired skills to continue doing so in the future, then you're not really earning a PhD.
Depends on the field. There aren't really all that many research tasks that can be completed in a week. One of my favorite stories from the past few decades was the finding of accelerating expansion of space. It took three decades of scheduling telescope time, looking at exactly the right places in space at exactly the right time, to find enough supernovas to have data to even analyze. Not a whole lot of non-trivial science is just "read existing literature, think hard, and produce text."
But honestly, there's a lot that is (particularly for simulation like stuff which can be implemented in code). We should expect to see a bunch of extra output here, which might improve scientific productivity (even though the real bottlenecks are gonna be the academic publishers and their fixation on holding on to their copyrights).
