I realize that it might be difficult to create a virtual all answering teacher bot. Even so. I think educational bots are important.
So to get started. I wonder if the conversation to the virtual teacher could be scripted. Like a movie you get a manuscript of a number of questions to write.
This makes it a lot easier for the programmer and everything about the subject will be asked. Many important questions would otherwise not be asked or answered.
With a database of a lot of question. The student could kinda make the process more personal anyway.
Say you have a number of important must write questions and a lot of optional questions.
Then the student could choose among the additional optional questions.
Why not just press a number in front a question instead of typing the question again as it is shown.
I believe if you retype the question. You will think about the question at least during the time you write it. This will make it easier to remember the question and learn the answer.
So the idea is to study by writing and choosing from a manuscript to a educational bot.