1. Factors influencing the usability of icons in the LCD touch screens Hsinfu Huang, Wang-Chin Tsai, Hsin-His Lai Department of Industrial Design, National Cheng Kung University, Taiwan, R.O.C. Graduate School of Design, National Yunlin University of Science and Technology, Taiwan, R.O.C.

2. Contents  1 Introduction  2 Methods  3 Results  4. Discussion and conclusions

3. Introduction  With the development of touch panel technology, LCD touch screens have different interactive type.  Compared to the type of gray screen in the past, current colored screen (16.7 million) seems more complicated.  Operation of a touch screen was different from the normal screen.

4. Introduction  Past times-we execute tasks that control cursors to the goal by normal display-control relation in the working environment of VDT.  Nowadays-With the development of touch panel technology, more and more touch screens are used widely. Lcd Touch Screen Application: POS, kiosk, medical environment and industrial control using. Icons icons play an important role in the computer graphic user interface. Icon design elements: styling quality, message quality, meaningfulness, locatability, and metaphor

5. Introduction  Computer graphic user interface (GUI) brings the visual operation to the user, and icons were often used on this interface Usability test questionnaire icons usability Factors a good touch-icon design will improve the user ’ s performance, and reduce its fault.

6. Introduction  Some of relevant studies determined anthropometry for workstation of touch-screen and make workstation more efficient. -Optimal viewing angle for touch-screen: between 19 and 54.5 degree off the horizontal [ Schultz et al. 1998]  There were few discussions on issues related to touching the target and icons using fingers. -A “ touch ” action involved in using a touch screen. -Some important icon design elements, including styling quality, message quality, meaningfulness, locatability, and metaphor [Huang et al., 2002]. -There was a principle not confirmed in the design of touch-screen icon.

7. Introduction  In order to create a high-user friendly interface, designers must understand the usability requirements, which must first be obtained from the users.  The purpose of this study was to investigate factors affecting the usability of icons in the LCD touch screens.  The findings could serve as a guide to design computer icons that were appropriate for touch screen interface, and make interface more user-friendly.

8. Methods-Experimental Design  Subjects -30 subjects participated in this experiment. -10 none-experience users 10 click-experience users (PDA user) 10 touch-experience users (LCD touch screen user). -mean age was 29.18  Materials & Stimuli - In the experimental interface, there were various design icons with different feedback level and they were classified along the axis.

9. Methods-Experimental Design The study makes usability of elements for touch-icons from relational journals. 20 items in Totally

10. Methods-Experimental Design  Subjects can experience the difference between operating the various touched icons.

11. Procedures  Subjects experienced all different interaction style, and perceived the different usability between operating the various touched icons.  After the touch task finished, subjects were asked to rate the usability elements based on the importance of touch icon.  Finally, subjects had to fill in the questionnaire and rated questions on 5-point Likert scales (1=not important at all; 5=most important).

12. Data analysis-  There were effective cases into the data analysis process. The following statistical methods were applied to data analysis: Descriptive statistical analysis Principal component analysis, and ANOVA.-  This study used the method of Principal Components Analysis to extract the factors of influencing the usability of icons in the LCD touch screens.

13. Data analysis- Principal Components Analysis Factor 1 Touch field Factor 2 Color quality Factor 3 Tactility Factor 4 Dynamics Factor 5 Hit quality Factor 6 Shape quality Factor 7 Semantics quality

14. Results Factors of usability  Factor 1:Touch field-icon spacing and size were influenced factors to human visual search---corner  Factor 2:Color quality- icons with apposite color were attractive to users and can display status changes. ---positive and negative connotations  Factor 3: Tactility-It produces faster and more accurate performance on the human-computer interface when haptic (touch and force feedback) feedback was added  Factor 4: Dynamics-Dynamics is a guide of icon design among them

15. Results Factors of usability  Factor 5:Hit quality- icons were instable or insensitive, users will have setbacks.  Factor 6:Shape quality- various shapes can draw attention to touch for users.  Factor 7:Semantics quality- Icons plus words were effective in computing situations

16. Results  Importance of the usability of elements -the averages that showed seven factors of usability from high mark to low mark were: Touch field, Semantics quality, Dynamics, Hit quality, Tactility, Color quality, Shape quality. This result indicated that subjects favor icon types that have practical function and high reliability.

17. Results  The difference in subjects ’ experience

18. Results  The difference in subjects ’ experience

19. Results  The difference in subjects ’ experience

21. Conclusion  For Subjects, the elements that directly interact with finger are main factors influencing the usability of icons, such as sweet spot, size, location and displacement.  Subjects were not favor visual elements on the touch-icons, such as shape and color, especially flash effect.  In this paper, the usability principles of touch-icon are constructed from experimental results. The relational results could serve as a guide to design touch-icons.

22.  Thank you for your attention