Clock Test

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Screen shot of PEBL's Clock Test


[edit] About

This is a test of sustained visual attention. An implementation of the so-called "Mackworth Clock Task". Watch a clock and determine when it skips a beat.

[edit] Notes

Run using the clocktest/clocktest.pbl file in the PEBL Test Battery.

[edit] Options

 pskip <- .4  #proportion of trials that jump
 gRad <- 240  #radius, in pixels, of clock circle
 gSize <- 9   #size of target
 trials <- 60 #Number of 1-second trials

[edit] Data Output

Raw data are saved to clock-x.csv in the clocktest/ directory

[edit] To Cite

Mueller, S. T. (2011). PEBL's Clock Test. Computer software retrieved from

[edit] References

  • Mackworth, N. H. (1948). The breakdown of vigilance during prolonged visual search. Quarterly Journal of Experimental Psychology, vol. 1, pp.6-21.
  • Shackel, B. (1999). How I broke the Mackworth clock test (and what I learned). In Hanson, M., Lovesey, E. J., and Robertson, S. A. Contemporary Ergonomics 1999. Taylor & Francis. (pp. 193-197)
  • Lichstein, K. L., Riedel, B. W., & Richman, S. L. (2000). The Mackworth clock test: A computerized version (statistical data included). The Journal of Psychology.

[edit] See Also

PEBL Test Battery

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