No abstract

This study explored an extended three-dimensional Fitts' law that is more suited for the pointing task than the conventional Fitts' law. The experiments were conducted under the manipulation of the distance to the target, size of the target, and direction of the target's location that can be described by two angles, 1 and 2. Considering the starting point as the center of coordinates, 1 is the angle between the positive z-axis and the target location and 2 is the angle between the positive y-axis and the projected target location on the x-y plane.From the experimental results, we confirmed that all four variables significantly affect the movement time. As we extended the index of difficulty of the conventional Fitts' model by incorporating 1 and 2, we established an extended Fitt's model that showed better accordance with the empirical data than the conventional Fitts' model, in terms of the r 2 and the standard error of the residual between the measured movement time and the predicted value.

No abstract

This study explored an extended three-dimensional Fitts' law that is more suited for the pointing task than the conventional Fitts' law. The experiments were conducted under the manipulation of the distance to the target, size of the target, and direction of the target's location that can be described by two angles, θ1 and θ2. Considering the starting point as the center of coordinates, θ1 is the angle between the positive z-axis and the target location and θ2 is the angle between the positive y-axis and the projected target location on the x-y plane. From the experimental results, we confirmed that all four variables significantly affect the movement time. As we extended the index of difficulty of the conventional Fitts' model by incorporating θ1 and θ2, we established an extended Fitts' model that showed better accordance with the empirical data than the conventional Fitts' model and 3D Fitts' law of Murata and Iwase, in terms of the r 2 and the standard error of the residual between the measured movement time and the predicted value.

The purpose of this research was to develop an integrated interface for the usability test of systems or products in the design process. It is capable of automatically creating GOMS models which can predict human task performances. It can generate GOMS models to be interacted with the prototype interfaces. It can also effectively manage various design information and various usability test results to be implemented into the new product and/or system design. Thus we can perform usability test for products or system prototypes more effectively and also reduce time and effort required for this test. For usability tests, we established an integrated interface based on GOMS model by the LabVIEW program. We constructed the system that the linkage to GOMS model is available. Using this integrated interface, the menu structure of mobile phone can be constructed easily. User can design a depth and a breath that he want. The size of button and the label of the button is changable. The path to the goal can be defined by the user. Using a designed menu structure, the experiment could be performed. The results of GOMS model and the actual time are presented. Besides, values of operators of GOMS model can be defined as the value that user wants. Using the integrated interface that we developed, the optimal menu structure deducted. The menu structure that user wants can be established easily. The optimal layout and button size can be decided by comparison of numerous menu structures. User can choose the method of usability test among GOMS model and empirical data. Using this integrated interface, the time and costs can be saved and the optimal menu structure can be found easily. 1) Keyword: GOMS model, rapid prototyping 1. 서 론 효율적인 사용자 인터페이스란 학습하기 쉽고 오류 발생이 적 으며 적은 노력으로 빠른 시간 내에 과제 목표를 달성할 수 있 는 것을 말한다. 이런 인터페이스를 개발하기 위해서는 '시제 품 개발 → 평가 → 분석 → 재설계'의 과정을 반복하게 되는데 이때 인터페이스가 시스템의 목적에 잘 부합되게 설계되었는 지 평가, 분석하는 것을 사용성 평가라고 한다(Butler et al., 1989). 이러한 사용성 평가를 가장 정확하게 실시하는 방법은 실제 시스템을 실제 사용자가 사용하게 하여, 배우기 쉽고 오류가 적으며 수행도가 좋은 지를 평가하는 것이다. 그러나 새로운 기술의 개발 주기가 매우 짧아지는 최근의 추세를 감안해 볼 때, 시스템 개발단계에서 제품의 프로토타입을 제작 및 개선