To implement current reforms regarding proof and reasoning in secondary school mathematics successfully, pre-service secondary mathematics teachers must have adequate understandings of concepts across mathematical domains for their future teaching. This paper examined the strategies that pre-service secondary mathematics teachers had for evaluating statements in the domains of algebra, analysis, geometry, and number theory. The results suggest that most preservice teachers rely on examples and their (partially) correct understandings of mathematical facts when determining the statement's veracity. The results also suggest that the majority of pre-service teachers accurately evaluate the validity of statements. [For the complete proceedings, see ED585874.]