Sandwich feedback: The empirical evidence of its effectiveness

This is a dataset from between-subject experiment that tested the effectiveness of “sandwich feedback. 91 university students solved 12 mathematical problems from the secondary-school curriculum. After the time limit, we assigned them randomly to one of three possible treatments. One group received negative computer-administrated feedback, describing the mistakes with their methods and solutions. The second group received sandwich feedback, which contained the same constructive critique, though sandwiched between two general, positive statements that were not related to the real respondents’ effort or performance. The third group did not receive any feedback. Afterwards, the respondents had 10 minutes to prepare for the second set of similar problems.