another lightspeed idea , using a plug in called " tell me about" what this plug in would do is when hal says something back in a general or random conversation, example hal says : corvairs were made from 1960 to 1969 . the user if interested in more info , could use the trigger words " tell me about " corvairs ( or tell me more about , or what else do you know about " ) then say the subject , hal would then search his data base on the subject word and any information he has learned on corvairs (or whatever) .
If hal doesn't have that subject in his data base to tell you information , hal can say that's something LIKE , i really don't know about that, do you know any more on the subject ?
if the user does he can say the information , hal would learn for later use with the plug in. if not the user doesn't have to say anything.