Manual and cognitive benefits of two-handed input: an experimental study

ABSTRACT

One of the recent trends in computer input is to utilize users' natural bimanual motor skills. This article further explores the potential benefits of such two-handed input. We have observed that bimanual manipulation may bring two types of advantages to human-computer interaction: manual and cognitive. Manual benefits come from increased time-motion efficiency, due to the twice as many degrees of freedom simultaneously available to the user. Cognitive benefits arise as a result of reducing the load of mentally composing and visualizing the task at an unnaturally low level which is imposed by traditional unimanual techniques. Area sweeping was selected as our experimental task. It is representative of what one encounters, for example, when sweeping out the bounding box surrounding a set of objects in a graphics program. Such tasks cannot be modeled by Fitts' Law alone and have not been previously studied in the literature. In our experiments, two bimanual techniques were compared with the conventional one-handed GUI approach. Both bimanual techniques employed the two-handed “stretchy” technique first demonstrated by Krueger in 1983. We also incorporated the “Toolglass” technique introduced by Bier et al. in 1993. Overall, the bimanual techniques resulted in significantly faster performance than the status quo one-handed technique, and these benefits increased with the difficulty of mentally visualizing the task, supporting our bimanual cognitive advantage hypothesis. There was no significant difference between the two bimanual techniques. This study makes two types of contributions to the literature. First, practically we studied yet another class of transaction where significant benefits can be realized by applying bimanual techniques. Furthermore, we have done so using easily available commercial hardware in the context to our understanding of why bimanual interaction techniques have an advantage over unimanual techniques. A literature review on two-handed computer input and some of the relevant bimanual human mototr control studies is also included.

REFERENCES

• 1: ANDERSON, J. R., Ed. 1980. Cognitive Skills and Their Acquisition. Lawrence Erlbaum Assoc. Inc., Hillsdale, NJ.
• 2: ANDERSON, J. R. 1982. Acquisition of Cognitive Skill. Psychol. Rev. 89, 4, 369-406.
• 3: Eric A. Bier , Maureen C. Stone , Ken Pier , William Buxton , Tony D. DeRose, Toolglass and magic lenses: the see-through interface, Proceedings of the 20th annual conference on Computer graphics and interactive techniques, p.73-80, September 1993 [doi>10.1145/166117.166126]
• 4: BUXTON, W. 1986. Chunking and phrasing and the design of human-computer dialogues. In Proceedings of the IFIP World Computer Congress on Information Processing 86 (Dublin, Ireland, Sept. 1-5), H.-J. Kugler, Ed. North-Holland Publishing Co., Amsterdam, The Netherlands, 475-480.
• 5: W. Buxton , B. Myers, A study in two-handed input, Proceedings of the SIGCHI conference on Human factors in computing systems, p.321-326, April 13-17, 1986, Boston, Massachusetts, United States
• 6: Stuart K. Card , Thomas P. Moran , Allen Newell, The keystroke-level model for user performance time with interactive systems, Communications of the ACM, v.23 n.7, p.396-410, July 1980 [doi>10.1145/358886.358895]
• 7: R. F. Dillon , Jeff D. Edey , Jo W. Tombaugh, Measuring the true cost of command selection: techniques and results, Proceedings of the SIGCHI conference on Human factors in computing systems: Empowering people, p.19-26, April 01-05, 1990, Seattle, Washington, United States [doi>10.1145/97243.97247]
• 8: FITTS, P. M. 1954. The information capacity of the human motor system controlling the amplitude of movement. J. Exper. Psych. 47, 6, 381-391.
• 9: FLOWERS, K. 1975. Handedness and controlled movement. Br. J. Stat. Psychol. 66, 1, 39-52.
• 10: GUIARD, Y. 1987. Asymmetric division of labor in human skilled bimanual action: The kinematic chain as a model. J. Motor Behav. 19, 4, 486-517.
• 11: GUIARD, Y. AND FERRAND, T. 1995. Asymmetry in bimanual skills. In Manual Asymmetries in Motor Performance, Elliott and Roy, Eds. CRC Press, Inc., Boca Raton, FL.
• 12: Ken Hinckley , Randy Pausch , John C. Goble , Neal F. Kassell, Passive real-world interface props for neurosurgical visualization, Proceedings of the SIGCHI conference on Human factors in computing systems: celebrating interdependence, p.452-458, April 24-28, 1994, Boston, Massachusetts, United States [doi>10.1145/191666.191821]
• 13: Ken Hinckley , Randy Pausch , Dennis Proffitt , Neal F. Kassell, Two-handed virtual manipulation, ACM Transactions on Computer-Human Interaction (TOCHI), v.5 n.3, p.260-302, Sept. 1998 [doi>10.1145/292834.292849]
• 14: Paul Kabbash , William Buxton , Abigail Sellen, Two-handed input in a compound task, Proceedings of the SIGCHI conference on Human factors in computing systems: celebrating interdependence, p.417-423, April 24-28, 1994, Boston, Massachusetts, United States [doi>10.1145/191666.191808]
• 15: KIRSH, D. AND MAGLIO, P. 1994. On distinguishing epistemic from pragmatic action. Cog. Sci. 18, 4, 513-549.
• 16: KRUEGER, M. 1983. Artificial Reality. Addison-Wesley, Reading, MA.
• 17: OWEN, R., KURTENBACH, G., FITZMAURICE, G., BAUDEL, T., AND BUXTON, W. 1998. Bimanual manipulation in curve-editing tasks, http://www'dgp'ut~r~nt~'ca/OTP/papers/bill'buxt~n/ CurveMatch.html.
• 18: PETERS, M. 1985. Constraints in the performance of bimanual tasks and their expression in unskilled and skilled subjects. Q. J. Exp. Psychol. 37A, 171-196.
• 19: POULTON, E. AND FREEMAN, P. 1966. Unwanted asymmetrical transfer effects. Psychol. Bull. 66, 1, 1-8.
• 20: POULTON, E. C. 1989. Bias in Quantifying Judgments. Lawrence Erlbaum Assoc. Inc., Hillsdale, NJ.
• 21: Emanuel Sachs , Andrew Roberts , David Stoops, 3-Draw: A Tool for Designing 3D Shapes, IEEE Computer Graphics and Applications, v.11 n.6, p.18-26, November 1991 [doi>10.1109/38.103389]
• 22: SCHMIDT, R. A., ZELAZNIK, H., HAWKINS, B., FRANK, J. S., AND QUINN, J. T. 1979. Motor-output variability: A theory for the accuracy of rapid motor acts. Psychol. Rev. 86, 5, 415-451.
• 23: SHNEIDERMAN, B. 1983. Direct manipulation: A step beyond programming languages. Computer 16, 8, 57-69.
• 24: SIMON, H. 1974. How big is a chunk. Science 183, 482-488.
• 25: SMITH, D. C., IRBY, C., KIMBALL, R., VERPLANK, W., AND HARSLEM, E. 1982. Designing the Star user interface. BYTE 7, 4, 242-282.
• 26: SUMMERS, J. J. AND KENNEDY, T. M. 1992. Strategies in the production of a 5:3 polyrhythm. Hum. Move. Sci. 11, 101-112.
• 27: SUTHERLAND, I. E. 1963. Sketchpad: A man-machine graphical communication system. In AFIPS Conference Proceedings. 329-346.
• 28: TODOR, J. I. AND DOANE, T. 1978. Handedness and hemispheric asymmetry in the control of movements. J. Motor Behav. 10, 295-300.
• 29: WACOM. 1994. Wacom UD-1212R, UD-1218R/RE and UD-1825R serial tablet user's manual. Wacom Technology Corp., Vancouver, WA.

INDEX TERMS

Primary Classification:
  H. Information Systems
  H.1 MODELS AND PRINCIPLES
      H.1.2 User/Machine Systems
          Subjects: Human factors

Additional Classification:
  H. Information Systems
  H.5 INFORMATION INTERFACES AND PRESENTATION (I.7)
      H.5.2 User Interfaces (D.2.2, H.1.2, I.3.6)
          Subjects: Interaction styles (e.g., commands, menus, forms, direct manipulation); Input devices and strategies (e.g., mouse, touchscreen)

  I. Computing Methodologies
  I.3 COMPUTER GRAPHICS
      I.3.6 Methodology and Techniques
          Subjects: Interaction techniques

General Terms:
Experimentation, Human Factors, Measurement

Keywords:
bimanual input, input devices, two-handed input