Actually - they dropped out because their marks were low (not because the courses were hard).

"The survey results also showed that the students who dropped out didn’t do so because they discovered an unexpected amount of the work ... The students switched out because they were dissatisfied with their grades ... What they didn’t expect is that even if they work hard, they still won’t do well."

This story relates to a discussion we had in our COMP650 course, but isn't specifically related to Social Computing. In that other discussion we discussed the relevancy of having course marks and barriers marks can present to learning.