At some universities students are asked to complete course evaluations in class in person i.e. everyone who is in class that day is given time to complete it; in structure may be sitting at the front of the class while evaluations are completed). at other university students complete course evaluations online i.e. it is optional to complete course evaluation; they are done at people's homes without interaction with other students

explain how the way course evaluations are administered in class or online could impact the external and internal validity of the questionnaire