This study investigated their views concerning evidence and expert opinion of 10th-grade students, accessed by an open-ended questionnaire in the context of a socio-scientific issue: the cause of flood disasters, and personal epistemology identified by the "Learning Environment Preference Questionnaire" (LEP). Students' responses to the open-ended questions showed that when thinking about the flood issue, most students rely heavily on direct and numerical data to draw their conclusions, while experts represented a source of conclusive information. The LEP scores indicated that, in terms of epistemological development, students were mostly at the stage of the "multiplicists" in Perry's model. The statistical analysis suggested that view towards evidence and expert were associated with personal epistemology.