Abstract
In order to minimize a biased view of evaluators in usability test, a multiple evaluation method so called Multi-Centered Usability Evaluation Method(MCUEM) was suggested and structured in this study. To use MCUEM, the existing evaluation methods were re-categorized into 'developer and evaluator-centered', 'evaluator-centered', 'user-centered', 'evaluator and user-centered', and the 'developer, evaluator, and user-centered methods. Furthermore, in order to verify the relevance of MCUEM, the usability of mobile phone was tested in this study. In results, it was found that different evaluation methods generated greatly different results, that showed the risk of using a particular usability method due to different perspectives of evaluators. At the same time, it was found that MCUEM could greatly minimize such biases. Therefore, it was concluded that using MCUEM could help the usability engineer design a test protocol with a minimal risk of bias due to different perspective of evaluators.