Five participants, I-4, I-7, I-10, I-11, and I-12, applied an s-character argument directly. For example, (I-4) "But I know this is sp where this is pure sp . My guess is probably just that. Since it is sp 2 hybridized, it forms a stronger bond compared to the other nitrogen which has a sp bond." When participants drew structures to support their reasoning, the structure of DBU was recopied with the hybridization of each atom indicated. The structures were not manipulated.