Abstract
The rationale for Fitts’ law is that pointing tasks have the information-theoretic analogy of sending a signal over a noisy channel, thereby matching Shannon’s capacity formula. Yet, the currently received analysis is incomplete and unsatisfactory: There is no explicit communication model for pointing; there is a confusion between central concepts of capacity (a mathematical limit), throughput (an average performance measure), and bandwidth (a physical quantity); and there is also a confusion between source and channel coding so that Shannon’s Theorem 17 can be misinterpreted. We develop an information-theoretic model for pointing tasks where the index of difficulty (ID) is the expression of both a source entropy and a zero-error channel capacity. Then, we extend the model to include misses at rate ε and prove that ID should be adjusted to (1−ε)ID. Finally, we reflect on Shannon’s channel coding theorem and argue that only minimum movement times, not performance averages, should be considered.
- ISO 9241-9:2000. 2000. Ergonomic Requirements for Office Work with Visual Display Terminals (VDTs) -- Part 9: Requirements for Non-keyboard Input Devices. ISO 9241-9:2000. International Organization for Standardization, Geneva, Switzerland.Google Scholar
- F. Attneave. 1959. Applications of Information Theory to Psychology: A Summary of Basic Concepts, Methods, and Results. H. Holt, New York.Google Scholar
- M. Bakaev. 2008. Fitts’ law for older adults: Considering a factor of age. In Proceedings of the 8th Brazilian Symposium on Human Factors in Computing Systems (IHC’08). Sociedade Brasileira de Computação, Porto Alegre, Brazil, 260--263. DOI: http://dl.acm.org/citation.cfm?id=1497470.1497502 Google ScholarDigital Library
- P. Bertelson. 1961. Sequential redundancy and speed in a serial two-choice responding task. Quarterly Journal of Experimental Psychology 13, 2 (1961), 90--102.Google ScholarCross Ref
- R. J. Bootsma, L. Fernandez, and D. Mottet. 2004. Behind fitts’ law: Kinematic patterns in goal-directed movements. International Journal of Human-Computer Studies 61, 6 (2004), 811--821. Google ScholarDigital Library
- D. J. Cannon and L. J. Leifer. 1990. Speed and accuracy for a telerobotic human/machine system: experiments with a target-threshold control theory model for Fitts’ law. In Proceedings of IEEE International Conference on Systems, Man and Cybernetics Conference (1990). IEEE, 677--679.Google ScholarCross Ref
- S. K. Card, W. K. English, and B. J. Burr. 1978. Evaluation of mouse, rate-controlled isometric joystick, step keys, and text keys for text selection on a CRT. Ergonomics 21, 8 (1978), 601--613.Google ScholarCross Ref
- O. Chapuis, R. Blanch, and M. Beaudouin-Lafon. 2007. Fitts’ Law in the Wild: A Field Study of Aimed Movements. LRI Technical Report Number 1480.Laboratoire de Recherche en Informatique, Orsay, France, 11 pages. http://insitu.lri.fr/ chapuis/publications/RR1480.pdf.Google Scholar
- Andy Cockburn, Carl Gutwin, and Saul Greenberg. 2007. A predictive model of menu performance. In Proceedings of the SIGCHI Conference on Human Factors in Computing Systems. ACM, San Jose, CA, 627--636. Google ScholarDigital Library
- T. M. Cover and J. A. Thomas. 2012. Elements of Information Theory. John Wiley 8 Sons, New Jersey.Google Scholar
- E. R. F. W. Crossman. 1957. The speed and accuracy of simple hand movements. Nature and Acquisition of Industrial Skills - DSIR 17/573. MRC and DSIR Joint Committee on Individual Efficiency in Industry.Google Scholar
- E. R. F. W. Crossman and P. J. Goodeve. 1983. Feedback control of hand-movement and Fitts’ law. The Quarterly Journal of Experimental Psychology 35, 2 (1983), 251--278. Originally presented at the Meeting of the Experimental Psychology Society, Oxford, 1963.Google Scholar
- Nicola Elia. 2004. When bode meets shannon: Control-oriented feedback communication schemes. IEEE Transactions on Automatic Control 49, 9 (2004), 1477--1488.Google ScholarCross Ref
- P. Elias. 1958. Two famous papers. IRE Transactions on Information Theory 4, 3 (1958), 99.Google ScholarCross Ref
- P. M. Fitts. 1953. The Influence of Response Coding on Performance in Motor Tasks, in Current Trends in Information Theory.University of Pittsburgh Press, Pittsburgh, PA.Google Scholar
- P. M. Fitts. 1954. The information capacity of the human motor system in controlling the amplitude of movement. Journal of Experimental Psychology 47, 6 (1954), 381.Google ScholarCross Ref
- P. M. Fitts. 1966. Cognitive aspects of information processing: III. Set for speed versus accuracy.Journal of Experimental Psychology 71, 6 (1966), 849.Google Scholar
- P. M. Fitts and J. R. Peterson. 1964. Information capacity of discrete motor responses.Journal of Experimental Psychology 67, 2 (1964), 103.Google Scholar
- J. M. Flach, M. A. Guisinger, and A. B. Robison. 1996. Fitts’s law: Nonlinear dynamics and positive entropy. Ecological Psychology 8, 4 (1996), 281--325.Google ScholarCross Ref
- K. Gan and E. R. Hoffmann. 1988. Geometrical conditions for ballistic and visually controlled movements. Ergonomics 31, 5 (1988), 829--839.Google ScholarCross Ref
- E. N. Gilbert. 1960. Capacity of a burst-noise channel. Bell System Technical Journal 39 (1960), 1253--1265.Google ScholarCross Ref
- J. Gori, O. Rioul, and Y. Guiard. 2017. To miss is human: Information-theoretic rationale for target misses in fitts’ law. In Proceedings of the ACM SIGCHI Conference on Human Factors in Computing Systems (CHI’17). ACM, Denver, 5. Google ScholarDigital Library
- Julien Gori, Olivier Rioul, Yves Guiard, and Michel Beaudouin-Lafon. 2017. One fitts law, two metrics. In Proceedings of IFIP Conference on Human-Computer Interaction. Springer, Berlin,525--533.Google ScholarCross Ref
- Y. Guiard. 1997. Fitts’ law in the discrete vs. cyclical paradigm. Human Movement Science 16, 1 (1997), 97--131.Google ScholarCross Ref
- Yves Guiard and Halla B Olafsdottir. 2011. On the measurement of movement difficulty in the standard approach to Fitts’ law. PLoS One 6, 10 (2011), e24389.Google ScholarCross Ref
- Y. Guiard, H. B. Olafsdottir, and S. T. Perrault. 2011. Fitt’s law as an explicit time/error trade-off. In Proceedings of the SIGCHI Conference on Human Factors in Computing Systems. ACM, New York, 1619--1628. Google ScholarDigital Library
- Y. Guiard and O. Rioul. 2015. A mathematical description of the speed/accuracy trade-off of aimed movement. In Proceedings of the 2015 British HCI Conference. ACM, New York, 91--100. Google ScholarDigital Library
- Peter A. Hancock and Karl M. Newell. 1985. The movement speed-accuracy relationship in space-time. In Motor Behavior. Springer, Berlin, 153--188.Google Scholar
- W. E. Hick. 1952. On the rate of gain of information. Quarterly Journal of Experimental Psychology 4, 1 (1952), 11--26.Google ScholarCross Ref
- E. R. Hoffmann. 2013. Which version/variation of fitts’ law? A critique of information-theory models. Journal of Motor Behavior 45, 3 (2013), 205--215.Google ScholarCross Ref
- R. Hyman. 1953. Stimulus information as a determinant of reaction time.Journal of Experimental Psychology 45, 3 (1953), 188.Google Scholar
- R. Kerr. 1973. Movement time in an underwater environment. Journal of Motor Behavior 5, 3 (1973), 175--178.Google ScholarCross Ref
- D. Laming. 2001. Statistical information, uncertainty, and bayes’ theorem: Some applications in experimental psychology. In Symbolic and Quantitative Approaches to Reasoning with Uncertainty, Salem Benferhat and Philippe Besnard (Eds.). Lecture Notes in Computer Science, Vol. 2143. Springer, Berlin, 635--646. Google ScholarDigital Library
- R. D. Luce. 2003. Whatever happened to information theory in psychology? Review of General Psychology 7, 2 (2003), 183--188.Google ScholarCross Ref
- I. S. MacKenzie. 1989. A note on the information-theoretic basis for Fitts’ law. Journal of Motor Behavior 21, 3 (1989), 323--330.Google ScholarCross Ref
- I. S. Mackenzie. 1992. Fitts’ Law as a Performance Model in Human-computer Interaction. Ph.D. Dissertation. University of Toronto. Google ScholarDigital Library
- I. S. MacKenzie. 2013. A note on the validity of the shannon formulation for fitts’ index of difficulty. Open Journal of Applied Sciences 3, 6 (2013), 360--368.Google ScholarCross Ref
- I. S. MacKenzie and W. Buxton. 1992. Extending fitts’ law to two-dimensional tasks. In Proceedings of the SIGCHI Conference on Human Factors in Computing Systems. ACM, New York, 219--226. Google ScholarDigital Library
- D. E. Meyer, R. A. Abrams, S. Kornblum, C. E. Wright, and J. E. Keith Smith. 1988. Optimality in human motor performance: Ideal control of rapid aimed movements. Psychological Review 95, 3 (1988), 340.Google ScholarCross Ref
- D. E. Meyer, J. E. Keith-Smith, S. Kornblum, R. A. Abrams, and C. E. Wright. 1990. Speed-accuracy Tradeoffs in Aimed Movements: Toward a Theory of Rapid Voluntary Action, in Jeannerod Attention and Performance. Lawrence Erlbaum Associates, Inc, New Jersey.Google Scholar
- G. A. Miller. 1956. The magical number seven, plus or minus two: Some limits on our capacity for processing information. Psychological Review 63, 2 (1956), 81.Google ScholarCross Ref
- Denis Mottet, Liesjet Elisabeth Henriette van Dokkum, Jérôme Froger, Abdelkader Gouaïch, and Isabelle Laffont. 2017. Trajectory formation principles are the same after mild or moderate stroke. PloS One 12, 3 (2017), e0173674.Google ScholarCross Ref
- Jörg Müller, Antti Oulasvirta, and Roderick Murray-Smith. 2017. Control theoretic models of pointing. ACM Transactions on Computer-Human Interaction 24, 4 (2017), 27. Google ScholarDigital Library
- U. Neisser. 1967. Cognitive Psychology. Englewood Cliffs: Prentice-Hall, East Norwalk, CT.Google Scholar
- A. Newell. 1994. Unified Theories of Cognition. Harvard University Press, Cambridge, MA. Google ScholarDigital Library
- R. Plamondon and A. M. Alimi. 1997. Speed/accuracy trade-offs in target-directed movements. Behavioral and Brain Sciences 20, 2 (1997), 279--303.Google ScholarCross Ref
- O. Rioul. 2007. Théorie de l’information et du codage. Hermes-Lavoisier, London, UK.Google Scholar
- O. Rioul and Y. Guiard. 2012. Power vs. logarithmic model of Fitts’ law: A mathematical analysis. Mathematics and Social Sciences 50.3, 199 (2012), 85--96.Google Scholar
- O. Rioul and Y. Guiard. 2013. The power model of Fitts’ law does not encompass the logarithmic model. Electronic Notes in Discrete Mathematics 42 (Jun. 2013), 65--72.Google Scholar
- O. Rioul and J. C. Magossi. 2014. On Shannon’s Formula and Hartley’s Rule: Beyond the mathematical coincidence. Entropy 16, 9 (2014), 4892--4910.Google ScholarCross Ref
- D. A Rosenbaum. 2009. Human Motor Control. Academic Press, Cambridge, MA.Google Scholar
- Q. Roy, Y. Guiard, G. Bailly, E. Lecolinet, and O. Rioul. 2015. Glass+Skin: An empirical evaluation of the added value of finger identification to basic single-touch interaction on touch screens. In Proceedings of IFIP International Conference on Human-Computer Interaction (INTERACT’15). Springer, Berlin, 55--71.Google Scholar
- R. A. Schmidt, H. Zelaznik, B. Hawkins, James S. F., and J. T. Quinn Jr. 1979. Motor-output variability: A theory for the accuracy of rapid motor acts.Psychological Review 86, 5 (1979), 415.Google Scholar
- Steven C. Seow. 2005. Information theoretic models of HCI: A comparison of the Hick-Hyman law and Fitts’ law. Human-Computer Interaction 20, 3 (2005), 315--352. Google ScholarDigital Library
- C. E. Shannon. 1948. A mathematical theory of communication. Bell System Technical Journal 27 (1948), 379--423.Google ScholarCross Ref
- C. E. Shannon. 1956. The bandwagon. IRE Transactions on Information Theory 2, 1 (1956), 3.Google ScholarCross Ref
- C. E. Shannon and W. Weaver. 1949. The Mathematical Theory of Communication. University of Illinois PressGoogle Scholar
- R. W. Soukoreff and I. S. MacKenzie. 2004. Towards a standard for pointing device evaluation, perspectives on 27 years of Fitts’ law research in HCI. International Journal of Human-computer Studies 61, 6 (2004), 751--789. Google ScholarDigital Library
- R. W. Soukoreff and I. S. MacKenzie. 2009. An informatic rationale for the speed-accuracy trade-off. In Proceedings of the IEEE International Conference on Systems, Man and Cybernetics (SMC’09). 2890--2896. Google ScholarDigital Library
- R. W. Soukoreff, J. Zhao, and X. Ren. 2011. The entropy of a rapid aimed movement: Fitts index of difficulty versus Shannon s entropy. In Proceedings of the IFIP Conference on Human-Computer Interaction. Springer, Berlin, 222--239. Google ScholarDigital Library
- A. T. Welford. 1960. The measurement of sensory-motor performance: Survey and reappraisal of twelve years’ progress. Ergonomics 3, 3 (1960), 189--230.Google ScholarCross Ref
- A. T. Welford, A. H. Norris, and N. W. Shock. 1969. Speed and accuracy of movement and their changes with age. Acta Psychologica 30 (1969), 3--15.Google ScholarCross Ref
- R. S. Woodworth. 1899. Accuracy of voluntary movement.The Psychological Review: Monograph Supplements 3, 3 (1899), i-144.Google ScholarCross Ref
- J. Wu, J. Yang, and T. Honda. 2010. Fitts’ law holds for pointing movements under conditions of restricted visual feedback. Human Movement Science 29, 6 (2010), 882--892.Google ScholarCross Ref
- R. W. Yeung. 2008. Information Theory and Network Coding. Springer, Berlin. Google ScholarDigital Library
- S. Zhai. 2004. Characterizing computer input with Fitts’ law parameters—The information and non-information aspects of pointing. International Journal of Human-Computer Studies 61, 6 (2004), 791--809. Google ScholarDigital Library
- S. Zhai, P. O. Kristensson, C. Appert, T. H. Andersen, and X. Cao. 2012. Foundational issues in touch-screen stroke gesture design-an integrative review. Foundations and Trends in Human-Computer Interaction 5, 2 (2012), 97--205. Google ScholarDigital Library
Index Terms
- Speed-Accuracy Tradeoff: A Formal Information-Theoretic Transmission Scheme (FITTS)
Recommendations
On multipath fading channels at high SNR
A noncoherent multipath fading channel is considered, where neither the transmitter nor the receiver is cognizant of the realization of the path gains, but both are cognizant of their statistics. It is shown that if the delay spread is large in the ...
Information-theoretic comparison of channel capacity for FDMA and DS-CDMA in a Rayleigh fading environment
In this paper, a comparative estimate of the channel capacity assigned to each user for frequency-division multiple-access (FDMA) and direct-sequence code-division multiple-access (DS-CDMA) schemes operating in a Rayleigh fading channel is presented. ...
Dirty-paper coding versus TDMA for MIMO Broadcast channels
We compare the capacity of dirty-paper coding (DPC) to that of time-division multiple access (TDMA) for a multiple-antenna (multiple-input multiple-output (MIMO)) Gaussian broadcast channel (BC). We find that the sum-rate capacity (achievable using DPC) ...
Comments