Dot Judgment

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Screen shot of PEBL's Dot Judgment Task


[edit] About

PEBL Dot Judgment Task: This sample task demonstrates the use of simultaneous interleaved staircase procedures to estimate thresholds.

Designed, loosely, after one described by Damos (1986). As described by Damos, the task is not very interesting. Once you get beyond 10-15 points, you are essentially guessing. Thus, it is modified in order to determine JND thresholds for 10,20,30,40 points, using and interleaved staircase procedure.

[edit] Notes

[edit] Options

  numReps <- 50  ##Number of repetitions

[edit] Data Output

Data are saved to:

  • dotjudgment\data\dots-X.csv (individual participant trial-by-trial)
  • dotjudgment\data\dots-pooled.csv (pooled trial-by-trial)
  • data\dots-summary-X.txt (summary stats for each participant)
  • data/dots-log.csv (basic log file about participant running)
  • data/dots-all.csv. (pooled summary stats--one line per participant)

in the dots-X.csv file, the columns are subnum, block, trial, practice, standard, thresh, side, corr, abstime, and rt

Here, block is the trial block, practice is whether these were practice trials, standard is the number of actual dots on the side with fewer dots, thresh is the current staircase-measured 50% threshold difference, so that standard+thresh is the number of dots on the greater side, side is the side on which the target is on (-1 is left is higher, +1 is right is higher), abstime is the absolute time in ms since the experiment started, rt is the response time of the trial (in ms).

[edit] Citation

Mueller, S. T. (2011). The PEBL Dot Judgment Task. Computer software retrieved from

[edit] References

Damos, D. L. (1986). Development of a Computer-Based Naval Aviation Selection Test Battery. NAVAL AEROSPACE MEDICAL RESEARCH LAB PENSACOLA FL.

[edit] See Also

PEBL Test Battery

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