The current studies of using decision-making trial and evaluation laboratory (DEMATEL) method assume that the survey results from a group of people are reliable. However, the assumption might not be always true. In this study, we propose an integrated approach of using corrected item-total correlation and split-half methods to evaluate the consistency from the survey data. A case is illustrated to show that the proposed approach can identify those who have different opinions from the others. From managerial implications, the decision maker can further examine whether these different opinions should be taken into consideration when DEMATEL method is used.