The Effects Of Human Finger And Chinese Character On Finger Interaction For Chinese Input

The development of touch technology makes it possible to handwrite Chineseusing various methods，for example, thumb input. In order to improve handwritingperformance and user experience, this study investigates the effects of human finger andChinese character on the finger interaction for Chinese input. An interaction model isestablished and consequently the design guidelines on usability are developed.The purpose of experiment1is to find the effects of human finger and Chinesecharacter on handwriting performance, testing six hypotheses on finger type, fingerlength, finger width, direction of stroke, number of strokes, and character structure. Inexperiment1,39participants handwrite characters of different types using both thumband index finger. These participants are different in finger length and width. The resultsindicate that1) performance of index finger input is better than that of thumb input,2)the performance of input with medium level in finger length/width is better than thatwith other levels in finger length/width,3) the performance of handwriting verticalstrokes is better than that of handwriting strokes of other directions. Multiple indicatorsare used to evaluate the finger interaction for Chinese input, including input time,accuracy, number of protruding strokes, number of rewritings, satisfaction, mentalworkload, preference and handwriting area.Furthermore, experiment2and experiment3investigate the effects of size of inputbox, location of input box, input method and display size on finger interaction forChinese input.110participants and50participants are invited to experiment2andexperiment3, respectively. Participants in both experiments are asked to handwrite on3.5-inch,5.5-inch,7.0-inch and9.7-inch devices through thumb, index finger and stylus.Experiment2focus on the size of input box, which has5levels (i.e.5%,10%,15%,20%and25%of display area). The experiment3focus on the location of input box,which has5levels (i.e. left-up, right-up, central, left-down and right-down). The resultsof experiment2and experiment3find the optimal size and location of input box inhandheld smart devices with four display size when using three input methods.Regardless of input method or display size,29.5mm×29.5mm input box leads tobetter handwriting performance and58.9mm×58.9mm leads to better subjectiveratings. Hand input on central location has the best handwriting performance and subjective ratings.Finger interaction for Chinese input model (FICIM) is established based onthe results of the three experiments. This model illustrates the influences ofcharacteristics of human finger (i.e. type, length and width), Chinesecharacter(i.e. direction of the stroke, number of strokes and character structure)and interface design issues(i.e. size of input box, location of input box, displaysize) on Chinese handwriting performance and subjective ratings. Moreover,Design guidelines on improving the usability of Chinese handwriting system aredeveloped with respect to input method, display size, size and location of inputbox, finger size, contact area, motor ability, texture perception, input position,character complexity, direction of the stroke, character structure, handwritingstyle, Chinese semantics.