A Study On The Performance Of Non-Directional Click Task With Different Initial-Terminal Positions Based On Fitts's Law

The click Task is the most typical operation task in the user's graphical interface.It is to use the pointing device to complete the screen positioning and target selection operations,and Fitts' s Law is the common law to predict its performance.Previous studies based on Fitts' s Law found that the moving distance of the click task,the target width,the direction of motion,and the terminal position of the target will affect the performance of the click task.And previous studies generally believe that when the above four conditions are the same,the performance of the click task is the same.However,such research ignores the initial position and has not yet verified the impact of the initial position and terminal position(initial-terminal positions)of the click task on operational performance.In this study,the initial-terminal positions are divided into three categories: center?edge,edge?center and edge?edge.The experimental method is used to explore the influence of the initial-terminal positions on the performance of non-directional(eight movement directions)click task,and revise the Fitts' s Law according to the data of the click task response under different experimental conditions,so that the revised law can better predict the operational performance.The study was divided into three studies and included four experiments.The first study is a confirmatory study,including experiment 1: Experiment 1 verifies the effects of two kinds of initial-terminal positions(center ? edge,edge ? center)on the performance of the target(single motion direction)click task;The second study is exploratory research,including experiment 2 and 3: Experiment 2 systematically explores the effects of two kinds of initial-terminal positions(center?edge,edge?center)on the performance of non-directional click task in the half-way condition;Experiment 3 explores the effects of three kinds of initial-terminal positions(center?edge,edge?center,edge?edge)on the performance of non-directional click task in the half-way and full-way conditions;The third study is the integration study,including experiment 4: Experiment 4 based on the empirical results of the above three experiments,studies the non-directional click task performance of different moving distances,target widths,and initial-terminal positions,and the Fitts' s Law is optimized using the least squares method,according to the data of the click task response time under different experimental conditions.The main results of this research experiments are as follows:(1)The initial-terminal positions and directions of movement together affect the performance of the click task.(2)The three kinds of initial-terminal positions affected the performance of the non-directional click task: when the directions are 45°,90° and 180°,the edge?center is faster than the center?edge significantly;And when the direction is 90°,the edge?center is faster than the edge?edge.(3)The influence of the four directions of positive and oblique motion on the performance of the click task is as follows: in the three positions of center?edge,edge?center,edge?edge,the response of the click task from fast to slow are leftbottom?right-top,vertical,horizontal,left-top?right-bottom direction.(4)According to the data of the click task response under different experimental conditions,a revised Fitts' s Law is proposed.This law can better describe the relationship of click task response time and moving distance,target width and direction of motion in the click task of three different initial-terminal positions,and has stronger applicability.This study explores the influence of the initial-terminal positions on the performance of non-directional click task,and further reveals the rules and characteristics of the influence of the positions and directions on the performance of the click task,and proposes a new Fitts' s Law,which can better predict the performance of the click task.In theory,this research enriches the research on the influencing factors of click task performance and perfects the Fitts' s Law.In the application,it helps to optimize the interaction design,prevent misoperation and improve the performance of the click task and user satisfaction.