The purpose of the study is to present a methodology based on the sensitivity (the ability to detect signal) of the user's fixation in the design and evaluation of products. Sensitivity provides a theoretical background in modeling the human eye movement using visual signal detection. When a visual search is on the way, more eye fixations are necessary to visually process complex and vague area. From the aspect of recognition, well-design information structures were hypothesized to have fewer number of fixation and high sensitivity because well-designed menu structures reflecting the users' mental model would be well match with the product's menu structure, resulting in reducing the number of fixations. In this study, we propose a methodology based on the analysis of the sensitivity of the user fixation to support the design and evaluation of a user-centered menu structure relative to the human perception of information structure.