In his story Asimov is setting a comparison between our ordinary life in which computers and computerized machines are playing a secondary or let us say an adjuvant role; and an imaginary future life in which computers have gained a principle, substantial and indispensable role in the life of the humans to the extent of replacing them in one of the most vital fields of life; i.e. TEACHING.
In my opinion computers and computerized machines can only replace "humans" in the fields of life that do not comprise human interaction and need no respect of the human feelings, intellectual differences and capabilities. And this point of view is highlighted in Asimov's short story. For instance, the mechanical teacher – UNCONCERNED with Margie's inability to answer the tests she had been given – had been giving her a test after test in geography resulting in her hatred for geography, for the mechanical teacher and above all for school: "Margie was scornful.' School? What's there to write about school? I hate school;'" unlike the ordinary human teacher, who would have respected her inability, tried to know her points of weakness and would have done all his best to strengthen them. Moreover, he may have used all the possible encouraging methods – ranging from a smile and a pat on the head to a small present given to the little girl – to gain her trust and in consequence making her love his subject.
Furthermore, for me, a school is not a mere building in which students spend hours learning and gaining knowledge. It is not walls, desks and blackboards. A school is teachers, is friends, is a whole lived life. A school is a small society in which students get acquainted with different types of people, gain experiences as well as friends and build up their own personalities. Therefore, it cannot be replaced by a computer situated in a closed room, with a metallic voice of a computerized teacher emanated from it.
Overall, it meseems that computers, robots, computerized machines, or whatever it will be their names, can only replace "humans" in the aspects or fields of life that requires no interaction with people – that needs no feelings. They can replace a man in a factory or in cleaning homes and streets, but when it comes to the fields that require understanding of the human feelings and respecting the human differences, this will be impossible.
A.Khalifa