Line Judgment Task
Description
A speed-accuracy tradeoff task based on Henmon (1910) where participants quickly discriminate which of two vertical lines is longer under varying deadline conditions.
About This Test
Participants view two vertical lines (one on the left, one on the right) and must judge which is longer before a visual timer expires. The task consists of multiple blocks with progressively shorter response deadlines (default: 10000ms, 2000ms, 1000ms, 700ms, 500ms), creating an increasingly difficult speed-accuracy tradeoff. Each block includes practice trials followed by experimental trials with balanced sampling of line length differences. A red timer bar animates to show remaining response time.
Test Details
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Scientific Background
Original Task References:
These references describe the original task that this PEBL implementation is based on.
- Henmon, V. A. C. (1911). The relation of the time of a judgment to its accuracy. Psychological Review, 18(3), 186-201.
Data Output
Creates two data files: (1) linejudgment-data-<subnum>.csv with trial-by-trial data; (2) linejudgment-report-<subnum>.txt with block-level summary statistics including accuracy rates and mean response times.
Example Data
| subnum | block | trial | blocktrial | deadline | usetimer | l1 | l2 | x1 | y1 | x2 | y2 | toolong | resp | corr | rt | time0 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| P-mkc14c8b-q8ge | 1 | P | P | 10000 | 1 | 110 | 120 | 919 | 498 | 999 | 487 | 0 | right | 1 | 2085 | 23783 |
| P-mkc14c8b-q8ge | 1 | P | P | 10000 | 1 | 120 | 110 | 918 | 490 | 999 | 495 | 0 | right | 0 | 1861 | 26397 |
| P-mkc14c8b-q8ge | 1 | P | P | 10000 | 1 | 110 | 111 | 920 | 493 | 1001 | 496 | 0 | left | 0 | 1628 | 28789 |
| P-mkc14c8b-q8ge | 1 | P | P | 10000 | 1 | 120 | 119 | 920 | 489 | 1000 | 491 | 0 | left | 1 | 900 | 30937 |
| P-mkc14c8b-q8ge | 1 | 1 | 1 | 10000 | 1 | 116 | 115 | 919 | 489 | 999 | 495 | 0 | left | 1 | 678 | 32358 |
| P-mkc14c8b-q8ge | 1 | 2 | 2 | 10000 | 1 | 118 | 112 | 919 | 495 | 998 | 490 | 0 | left | 1 | 813 | 33558 |
| P-mkc14c8b-q8ge | 1 | 3 | 3 | 10000 | 1 | 113 | 120 | 918 | 497 | 1002 | 486 | 0 | right | 1 | 1135 | 34892 |
| P-mkc14c8b-q8ge | 1 | 4 | 4 | 10000 | 1 | 120 | 110 | 919 | 485 | 1000 | 500 | 0 | left | 1 | 649 | 36555 |
| P-mkc14c8b-q8ge | 1 | 5 | 5 | 10000 | 1 | 117 | 112 | 918 | 494 | 1001 | 491 | 0 | left | 1 | 605 | 37735 |
Sample data showing typical output format. Actual values will vary by participant.
About This Test
A speed-accuracy tradeoff task based on Henmon (1910) where participants quickly discriminate which of two vertical lines is longer under varying deadline conditions.
Category: Processing Speed
Estimated Duration: 10 minutes
Available Translations: 7 languages
Documentation Sources:
Test description file, Test implementation, Parameter schema
Documentation Status: Complete