The Response Report can be used to view both those students who have and haven't responded to the report. You must first create a student selection of those students you want to report on. Then go to the form's Response Report. If you want to see the students who have responded to the form, change the last filter from 'Current Responses' to 'Current Selection Responders'. If you want to see those who have not responsed, change it to 'Current Selection Nonresponders'