The Study on the Seamless Experience in Multi-level Devices: The Charging Electric Vehicle

Abstract

Background Due to the support to environmental preservation, purchasing an electric vehicle is in demand. In an electric vehicle charging process, a manless system is introduced. Users must charge their cars directly by using a mobile application and a charging station kiosk. Therefore, this study aims to investigate how the similarity of a mobile application with a charging station kiosk in electric vehicle charging tasks affects user’s experience. Methods This study was categorized into three parts. First, through a literature review, the task of electric vehicle charging, the factor of a screen user interface(UI), and the factor of providing a seamless experience in multi-level devices and usability test was determined. After a literature review, a case analysis was conducted. Using the factor of screen UI and the factor of providing a seamless experience in multi-level devices, criteria for judging screen similarity was determined. Second, three corporations(KEPCO PLUG, G-CHARGER, EVER ON) were compared and analyzed for the mobile application and kiosk by using the criteria. Third, a usability test for charging the electric vehicle by using the think-aloud method was conducted. At the same time, a survey that is based in heuristic evaluation was conducted. Results The synthesis of the case analysis in three corporations showed similarity in the screen ratio of width and length, and the ratio of the UI factor and the icon expression between mobile application and the charging station kiosk. The results of the case analysis showed a sequence of the higher similarity of the screen ratio, and the sequence of the higher similarity of the icon expression according to the results of the usability test. Then, there is a sequence of less error. And also, the corporation resulted in less error in providing the screen in all devices in the usability test results. The results of less error in the usability test were the same as the sequence of the higher score in the results of the satisfaction survey. Through, this study provides factors of seamless design for devices in charging electric vehicles. Using more icons than text could reduce errors in using devices. And also, increasing similarity of icon expression, icon color, and the ratio of the icon could also reduce the error in using devices. Conclusions The results of the study could offer a standard in multi-level devices user experience conditions for the screen. This study proves that the design factor of provided devices by charging electric vehicle corporations affects user experience by using a usability test. This study suggests the importance of similarity of multi-level devices by comparing and analyzing case analysis and usability test.