the computer can play at grandmaster level, but can it communicate at the level of a beginner or intermediate player and address their specific weaknesses and coach them to overcome them?

If someone builds such software the creators will become very rich, but until then human coaches will always have a place.

The beginner won't learn much being decimated by the computer again and again. But all players cannot help but to tighten their game with repeated practice against the computer and will probably become less blunder-prone.

Computers are great for some things, like tactics drills, but so far it takes a human to point out that you are doing the same type of thing wrong a lot.

A teacher continues to be indispensible.

Myself, never had one nor even a mentor. Closest thing for me was a stronger chess buddy.

Teachers are far more betetr then computers..

But teachers can use computers help to get tactical positions then help out with students etc..

Not just beginner and intermediate players. A good coach will always be an asset at all levels. I only need to mention the new Carlsen and Kasparov partnership..

...and teachers can use computers too to set up lessons like in chess mentor.

I bet that a human coach that sits in front of you, that knows your specific faults and potentialities is something even better, where for "better" I mean "that will let you improve faster".

But nowadays instruments can "bring the coach" very next to you, and I'm positively impressed. On the other side, I don't think that playing against a mere calculator will lead you anywhere, if not for your own "deduction" over your own, computer-proven, faults. But it seems a process way slower..and it's not "coaching".

More than from a "calculator" I bet you can learn more from a book, instead. In the meanwhile, you can exercise with the tactics drill etc on the pc.

Touche.