text: In the article it said, "a classroom computer could recognize when a student is becoming confused or bored." When students are on a computer atempting a lesson, it can calculate their expressions and send feedback to the teacher. If the teacher wants to, they can modify the lesson if the feedback wasn't good. For example, the students can frown if they don't like it, and smile if they do. It's a good way for a teacher to get feedback of what the students actually think.