Figure 1From: How should we teach tree-thinking? An experimental test of two hypothesesProportion of groups that correctly answered each question on two in-class tree-thinking activities. Four questions were unique to each activity: the building (Bu) and analyzing (An) questions and five questions were present in both (Bo). If the bars cross the dotted red line, then >80% of student groups answered the question correctly. The actual questions are provided in Additional file 1: Supplement 1 and Additional file 1: Supplement 2.Back to article page