Students would not be happy that a machine reads your face to tell a teacher how your feeling. Sometimes people want to be left alone because they are sad or mad. So having this machine woud not be good to have because some teacher could be nosy and ask why are you mad or sad. The machine cold also tell if your lying.

Sometimes you got to lie, so you could be left alone. Students would probably skip school because of this machine. Lots of schools will be empty because students do not want teachers to know about them. This machine could be used in pictures or face portates to see how the person in the picture is feeling, but to use it on students then no.

The police could use this machine to find out if criminals are lying about what they did. Parents would also be mad that teachers are using the machine on their children. There is no point of teachers using this machine. They do not need to know how your feeling at all. The teacher only us it for a reason or when nessasary not when they just feel like it.