Junco (2013) conducted a study about the use of Facebook by students. A random sample of students from a small U.S. university was contacted via email and asked to compete a survey. One of the questions asked in the survey was: On average, how many times per day do you check Facebook? Please give your answer as a number

Which one of the following types of error would not be a potential source of nonsampling error in this survey?

(1) Survey-format effects (2) Selection bias (3) Question effects (4) Behavioural considerations (5) Self-selection bia