text: One reason i dont think its valuable because emotions can change at any moment .Saying someone is 80% happy in a pictuer wouldnt always be ture becuase they could be smiling but also could be more sad than they are happy. Some people have a bipolar disoder which makes their eomtion change very fast , and some people are just very temperamental. Some students show emotions differnt than others . For example one student that is very upset could be yelling and shouting about it and another student that as angery as the other student could be very calm about it and not showing that they are angery.