Design strategies for GUI items with touch screen based information systems

Touch screens are a popular method of interaction with information systems embedded in public kiosks and PDAs. Typical information systems are used on desktop PCs and therefore restricted to having a mouse as the selection device used to interact with the system. The purpose of this study is to investigate how effective a touch screen is in selecting typical GUI items used in information systems. A series of tests were completed involving multi directional point and select tasks. A mouse, being the standard selection device, was also tested so the results of the touch screen could be compared and evaluated against. The GUI items tested were a button, check box, combo box and a text box. The touch screen used was a 17" Magic Touch USB overlay. During the test, data relating to movement time, error rate and throughput were captured. The results showed that the touch screen overlay was not suitable in terms of selecting small targets with a size of 8mm or less. There was a significant difference between the touch screen and the mouse in terms of movement time and error rate. The touch screen overlay was 15% slower than the mouse and had a 61% error rate compared to the error rate of 2.7% for the mouse. There was no significant difference in throughput between a touch screen overlay and mouse. Both selection devices had throughput of 1.2 bps. User satisfaction relating to each device was evaluated using responses to a device assessment questionnaire, completed by each participant at the conclusion of the test. The mouse was rated easier to use and easier to make accurate selections with. Both results were statistically significant (p < 0.05). The question regarding arm, wrist and finger fatigue was also statistically significant with the touch screen rated worse than the mouse. The report concludes with some practical implications of the study; namely that a touch screen overlay used only with a finger is not a practical selection device to use with typical information systems.UnpublishedApple Computer, I. (2004). "Apple Human Interface Guidelines." 155 - 192. Retrieved June 10, 2004, from http:ildeveloper.apple.com/documentation/UserExperience/Conceptual/OSXHIGuidelines/index.html Bender, G. T. (1998). Touch selection strategies for touch screens. Unpublished raw data. Bender, G. (1999). Touch screen performance as a function of the duration of auditory feedback and target size. Liberal Arts and Sciences, Wichita State _University: 7. Booth, K., Fisher, B., Po, B. (2004). "Mouse and Touchscreen Selection in the Upper and Lower Visual Fields." Human Factors in Computing Systems, CHI '2004 Conference Proceedings: 359-366. Douglas, S. and A. Mithal (1994). "The effect of reducing homing time on the speed of a frnger-controlled isometric pointing device." Human Factors in Computing Systems, C141 '94 Conference Proceedings: 411 - 416. Dumas, J. and J. Redish (1993). A Practical Guide to Usability T esting. New Jersey, U.S.A, Ablex publishing Corporation. Ferguson, E. and R. Gibson (2004). Development of an innovative tool to improve complementary feeding practices in the south-east Asian and pacific regions, University of Otago, New Zealand. Harada, H., Katsuura, T., Kikuchi, Y. (1996). "Fundamental study on the size and inter-key spacing of numeric keys for touch screen." Journal of Human Ergology 25(2): 167-174. ISO (1998). Ergonomic requirements for office work with visual display terminals (VDTs). Part 9 - Requirements for non keyboard input devices ( ISO 9241-9). International Organization for Standardization. MacKenzie, I., Sellen, A., & Buxton, W. (1991). A comparison of input devices in elemental pointing and dragging tasks. Proceedings of the CHI '91 Conference on human Factors in Computing Systems (pp. 161-166). New York: ACM. MacKenzie, S., Douglas, S., Kirkpatrick, A. (1999). "Testing pointing device performance and user assessment with the ISO 9241, part 9 standard." MacKenzie, S. and S. Jusoh (2001). "An Evaluation of Two Input Devices for Remote Pointing." Proceedings of the Eighth IFIP Working Conference on Engineering for Human- Computer Interaction EHCI 2001: 235-249. MacKenzie, S., Kauppinen, T., Silfverberg, M. (2001). "Accuracy measures for evaluating computer pointing devices." MacKenzie, S. and A. Oniszczak (1998). "A comparison of three selection techniques for touchpads". MacKenzie, S. and W. Soukoreff (1995). "Generalized Fitts' Law Model Builder." Mosaic of Creativity. Mass Multimedia, I. (2002). Comparing touch technologies. Colorado Springs, U.S.A. Retrieved June 12, 2004, from http://www.touchscreens.com/intro-touchtypes.html. Mayhew, D. (1992). Principles and guidelines in software user interface design, PTR Prentice-Hall, Inc. Nielsen, J. (2001). Usability metrics, Retrieved June 30, 2004, from http://www.useit.com/alertbox/20010121.html. NextWindow (2001). Competitive touchscreen technology. Auckland, New Zealand. Retrieved June 12, 2004, from http://www.nextwindow.com/technology/competitive.html. Preece, J. (1993). A guide to usability: human factors in computing, Addison-Wesley. Preece, J., Yvonne, R., Sharp, H. (2002). Interaction design: beyond human-computer interaction, John Wiley & Sons, Inc. Scholtz, J., Salvador, T., Lockhart, P Newbery, (1997). "Design: No job too small." Sears, A., Revis, D., Swatski, J., Crittenden, R, Shneiderman, S. (1993). "Investigating touch screen typing: The effect of keyboard size on typing speed." Behaviour & Information Technology 12: 17-22. Sears, A. and B. Shneiderman (1991). "High precision touchscreens: design strategies and comparisons with a mouse." International Journal of Man-Machine Studies 34: 593-613. Shneiderman, B. (1991). "Touchscreens now offer compelling uses." IEEE Software 8(2): 93- 94. Wilson, K. S., Inderrieden, M., Liu, S. (1995). "A comparison of live user interface devices designed for point-of-sale in the retail industry." Proceedings of the Human Factors & Ergonomics Society 39th Annual. Meeting 39: 273-277