In Peer Evaluation in Blended Team Project-Based Learning: What Do Students Find Important?, Hye-Jung & Cheolil (2012) describe "social loafing" as a negative aspect of collaborative learning. Social loafing may include insufficient performances by some team members as well as a lowering of expected standards of performance by the group as a whole to maintain congeniality amongst members. These authors said that because teachers tend to grade the finished product only, the social dynamics of the assignment may escape the teacher's notice.[10]