Effects of Practice with Foot- and Hand-Operated Secondary Input Devices on Performance of a Word-Processing Task Fredrick P. Garcia Kim-Phuong L. Vu Center for Usability in Design and Accessibility California State University, Long Beach

Keyboard and mouse are commonly used with the computer  No good alternative to the keyboard  Mouse works well with GUIs  Hands work quickly and accurately

Performance might improve when multiple effectors provide input  Mouse and trackball add to cumulative trauma disorders [1, 2, 3]  Hands-only adds homing time [4]  Opportunity to carry out tasks in parallel  Possibly reduced switch cost using different effectors [5]

Previous research found the foot slower than the hand but…  All previous research shows slower performance with the foot [7, 8, 9]  None of the research equated ability or familiarity using foot and hand devices explored practice with the foot explored word processing tasks requiring foot and hand input

What happens when participants get practice with a foot controlled device?  Commercial foot specific input device  Tasks requiring keyboard and secondary device input  Hand input device that is not overpracticed  Practice with the input devices

Two hypotheses on performance with practiced foot and hand devices  H1: Practice will improve performance regardless of device.  H2: Practice will improve performance more with the foot mouse than with the hand trackball. (performance measured by total time for task completion)

Experiment Schedule Test-session 1 Session 1 (prepractice) Practice-sessions Sessions 2 – 9 Test-session 2 Session 10 (postpractice) Practice hand trackball group (8) Test hand trackball (not practiced) Practice hand trackballTest hand trackball (practiced) Test foot mouse (not practiced) No practice with foot mouseTest foot mouse (not practiced) Practice foot mouse group (8) Test foot mouse (not practiced) Practice foot mouseTest foot mouse (practiced) Test hand trackball (not practiced) No practice with hand trackball Test hand trackball (not practiced)

Sample practice session screens 1. Click the Start Block of Trials button 2. Scroll down to find the 1 button and click on it 3. Scroll down to find the text to be highlighted; select the text 4. Scroll up to find the 2 button and click on it 5. When ready for the next trial, click the Start next Trial button

Task 1

Task 2 d 2 (r v 1 )/dt 2 =-   r v 1 /r v 3 +  m (-d mv /d mv 3 -r m /r m 3 )

Task 3 Scroll down

Task 4 The teacher had the students turn to Section 2 in their Modern Mathematics 1 textbook, which had replaced their previous text: Old Math 2. The day’s math lesson was on variables together with exponents, like x 5. The teacher was going to review the Pythagorean Theorem 3, where a 2 + b 2 = c 2, as an example. She also wanted to talk about finding the area of a circle using the formula r 2, where r stands for the circle’s radius. After Math, she was going to give a Chemistry lesson. She was going to begin by discussing H 2 O, which she was sure everyone would know about.

Performance on Test Sessions 1 and 2 T1 T2 T3T4

Practice improved performance with the foot mouse; not the hand trackball  H1 – Practice improves performance regardless of device  H2 – The foot shows more improvement with practice than the hand Not Supported Supported

Thank You

1.Jensen C., Borg, V., Finsen, L., Hansen, K., Juul-Kristensen, B., Christensen, H.. Job Demands, Muscle Activity and Musculoskeletal Symptoms in Relation to Work with the Computer Mouse. Scandinavian Journal of Work and Environmental Health 24, (1998) 2.Fagarasanu, M., Kumar, S.. Carpal Tunnel Syndrome Due to Keyboarding and Mouse Tasks: A Review. International Journal of Industrial Ergonomics 31, (2003) 3.Burgess-Limerick, R., Shemmell, J., Scadden, R., Plooy, A.. Wrist Posture During Computer Pointing Device Use. Clinical Biomechanics 14, (1999) 4.Card, S.K., Moran, T.P., Newell, A.. The Keystroke-Level Model for User Performance Time with Interactive Systems. Communications of the ACM 23(7), (1980) 5.Monsell, S.. Task Switching. TRENDS in Cognitive Sciences 7(3), (2003) 7.Pearson, G., Weiser, M.. Exploratory Evaluation of a Planar Foot-Operated Cursor- Positioning Device. In: J. J. O'Hare (ed.), Proceedings of the SIGCHI Conference on Human Factors in Computing Systems - CHI ’88, pp ACM Press, New York (1988) 8.Springer, J., Siebes, C.. Position Controlled Input Device for Handicapped: Experimental Studies with a Footmouse. International Journal of Industrial Ergonomics 17, (1996) 9.Pakkanen, T., Raisamo, R.. Appropriateness of Foot Interaction for Non-accurate Spatial Tasks. In: CHI '04 Extended Abstracts on Human Factors in Computing Systems, pp ACM Press, New York (2004) References

Comparisons of Foot Mouse and Hand Trackball Before and After Practice T1 T2 T3T4

Average Participant Familiarity and Comfort Ratings of Input Devices Rated aspect of devicePracticed deviceRated device Hand trackballFoot mouseHand mouse Comfort on Day 1 Hand trackball Foot mouse Comfort on Day 10 Hand trackball Foot mouse Familiarity on Day 1 (from Demographic Qs) Hand trackball Foot mouse Familiarity on Day 10 Hand trackball Foot mouse

Average Participant Familiarity and Comfort Ratings of Input Devices Rated aspect of devicePracticed deviceRated device Hand trackballFoot mouseHand mouse Comfort on Day 1 Hand trackball Foot mouse Comfort on Day 10 Hand trackball Foot mouse Familiarity on Day 1 (from Demographic Qs) Hand trackball Foot mouse Familiarity on Day 10 Hand trackball Foot mouse