Attention
Line Angle Matching
Also called: line orientation task, line orientation judgment, angle matching task, visuospatial judgment task
Measure how accurately people judge line angles: match two short lines to a fan of 13 numbered lines, with items balanced for left and right.
6-8 minUntimed
Free to start: 10 free participants per account, then $0.99 per participant for academic research, or any yearly plan. Preview any test free after you sign up.
- Papers, 2021 to 2025
- 95
- Evidence grade
- C
- Registered clinical studies
- 69
What it measures
A measure of judging the angle of lines. Each item shows two short lines above a fan of 13 numbered lines, 15 degrees apart, and participants choose the two fan lines at the same angles. The 32 items come in left and right mirror pairs and are the same for everyone, with no time limit. The score is the percent of items with both lines right.
Constructs
- Judging line orientation
- Visuospatial perception
- Left and right balance in spatial judgment
Research uses
- Visuospatial perception research
- Aging and neurodegenerative disease research
- Studies of left and right spatial bias
How the paradigm works
Line Angle Matching measures how accurately people judge the angle of lines, a visuospatial skill tested with no time pressure and almost no movement. Each item shows two short lines above a fan of 13 numbered lines, 15 degrees apart, from pointing left to pointing right. Each short line is a piece of one fan line, at the same angle and on the same side of the fan's center, taken from the inner, middle or outer part of that line. Participants select the two matching fan lines and press Next; a selection can be undone before Next.
More about the paradigm
The task follows the line orientation paradigm of Benton, Varney and Hamsher (1978), with items ConductScience wrote for it: 16 items whose two lines lie mostly right of straight up, 30 to 135 degrees apart, each shown with its left-right mirror image, so the 32 items are balanced for the two sides (Treccani and Cubelli, 2019). The items and their order are fixed, so every session sees the same test. Three practice items come with feedback that marks the right lines. The standard form takes about 6 minutes; the short form is the first 16 items, 8 items and their mirrors.
The main score is the percent of items with both lines right. The mean angle error, single lines right and percent correct on the right-side and left-side items are also reported. Scores support research and do not diagnose.
Scores
- Percent Correct%
- Items with both fan lines right, as a percent of the items answered.
- Higher is better
- Mean Angle Errordegrees
- Mean over items of the angle between the chosen lines and the right ones, pairing them the way that gives the smaller error.
- Lower is better; 0 when every item is right
- Items Correctcount
- Items with both fan lines right.
- Higher is better
- Lines Correctcount
- Single fan lines chosen right, two possible per item.
- Higher is better
- Right-Side Items Correct%
- Percent correct on the items whose two lines lie mostly right of straight up.
- Compare with the left-side items for a difference between the sides
- Left-Side Items Correct%
- Percent correct on the mirror images of those items, whose lines lie mostly left of straight up.
- Compare with the right-side items for a difference between the sides
- Median Item Timems
- Median time from an item's onset to Next.
- Informational; the test has no time limit
- Items Answeredcount
- Items answered in the scored run.
- Fewer than planned is flagged for review
- Planned Itemscount
- Items in the form that ran: 32 in the standard form or 16 in the short form.
- Informational
Use and evidence
95 papers from 2021 to 2025 name this task in their title or abstract, up 9% compared with 2016 to 2020. That ranks it 193 of 395 test families in our census. See the counts for every test.
Show the numbers
| Year | Papers |
|---|---|
| 2025 | 25 |
| 2024 | 23 |
| 2023 | 21 |
| 2022 | 15 |
| 2021 | 11 |
| 2020 | 20 |
| 2019 | 17 |
| 2018 | 16 |
| 2017 | 15 |
| 2016 | 19 |
| 2015 | 17 |
| 2014 | 20 |
| 2013 | 15 |
| 2012 | 13 |
| 2011 | 14 |
| 2010 | 11 |
| 2009 | 8 |
| 2008 | 21 |
| 2007 | 3 |
| 2006 | 8 |
| 2005 | 8 |
| 2004 | 5 |
| 2003 | 8 |
| 2002 | 4 |
| 2001 | 3 |
| 2000 | 6 |
Use grade D
30 to 99 papers from 2021 to 2025.
Evidence grade C
At least 2 test-retest papers, 30 reliability or validity papers or 3 registered clinical studies.
- Papers on test-retest reliability
- 3
- Papers on reliability or validity
- 67
- Registered clinical studies using it as an outcome
- 69
How the grades work
Use: A is 1,000 or more papers from 2021 to 2025, B 300 to 999, C 100 to 299, D 30 to 99 and E fewer than 30. Evidence: A means at least 25 papers report its test-retest reliability and at least 25 registered clinical studies use it as an outcome; B, at least 8 test-retest papers, and either 5 registered clinical studies or 150 reliability or validity papers; C, at least 2 test-retest papers, 30 reliability or validity papers or 3 registered clinical studies; D, little published measurement evidence found. The counts measure use. They include every paper that names the task in its title or abstract. Grades describe the published research on this task, not ConductCognition's version of it.
Source: ConductCognition test census 0.14.0, counted 31 October 2026 from OpenAlex and ClinicalTrials.gov.
Task design
The trial sequence as the test runs in ConductCognition.
- Display
- Two short lines above a fan of 13 numbered lines, 15 degrees apart, from pointing left (line 1) to pointing right (line 13). Each short line is the inner, middle or outer part of one fan line, at the same angle and on the same side.
- Answer
- Click or tap two fan lines, then Next. Selecting a line again undoes it, and a third choice replaces the first. No time limit, with 300 ms between items.
- Items
- 32 in a fixed order (standard; 16 in the short form): 16 items whose lines lie mostly right of straight up, 30 to 135 degrees apart, and their 16 left-right mirror images.
- Practice
- 3 items, with feedback that marks the right lines for 2,500 ms.
- Scores
- Percent of items with both lines right, mean angle error in degrees, single lines right, and percent correct on the right-side and left-side items.
- Screen
- The figure scales to the screen as a whole, so its angles need no calibration. Desktops, laptops and tablets of at least 700 by 900 pixels.
The paradigm follows Benton, Varney and Hamsher (1978), whose test has 11 lines 18 degrees apart and items of its own. This version has its own fan, items and name, so published norms for that test do not apply.
Quality checks
Each session is marked valid, needs review or invalid, with the reason, before you see its scores.
Scored rows: line_angle_matching_test from the scored run, a choice of two of 13 fan lines with no time limit. An item is right only when both lines are (chance 1 in 78). Accuracy not above chance is flagged, and the same two lines on 90% of answers invalidates when accuracy is not above chance. Answers under 200 ms on at least half the items invalidate. A run short of its planned items is flagged for review.
Why these rules
Accuracy significantly below chance (one-sided exact test, p < .05) cannot come from guessing; it means the response mapping was reversed or the task was not followed (Slick, Sherman and Iverson 1999 treat below-chance forced-choice performance as definite response bias). Chance-level accuracy can be a real result in impaired participants, so it is only flagged. One option on at least 90% of answered trials, when the correct options are balanced and accuracy is not above chance, means the answers did not depend on the items (the task counterpart of long-string responding in surveys; Curran 2016). An answer under 200 ms is faster than a simple visual reaction, so it cannot reflect the item. Following response-time effort screening for untimed tests (Wise and Kong 2005), the session is invalid only when at least half the answers are that fast. Each item's right pair is different, so the same answer on nearly every item cannot follow the items.
Running this test
Settings you can change
| Setting | Standard | Allowed |
|---|---|---|
| Form | Standard (32 items) | Standard (32 items), Short (16 items) |
Yearly plans can change settings within these limits. Free and pay-as-you-go studies use the standard settings.
Need a setting this test does not have?
Devices and languages
- Untimed test: runs on desktops, laptops and tablets. Participant devices
- Languages: English, Spanish, French, German, Italian, Portuguese (Brazil), Chinese (Simplified) and Japanese.
- Available on: Every plan, including the free plan.
- Recruiting online? See the setup guides for Prolific, Sona Systems, CloudResearch Connect and Qualtrics.
Cite and describe
Participants completed the Line Angle Matching task in a web browser (ConductCognition task version 1.0.0, scoring version 1.0.0; Benton, Varney and Hamsher, 1978; Treccani and Cubelli, 2019), with the standard settings (form: Standard (32 items)). The main score was percent correct (items with both fan lines right, as a percent of the items answered).
ConductCognition versions: task version 1.0.0, scoring version 1.0.0. Every export records the versions each session used, for a methods section.
- Benton, A. L., Varney, N. R., & Hamsher, K. deS. (1978). Visuospatial judgment: A clinical test. Archives of Neurology, 35(6), 364-367. https://doi.org/10.1001/archneur.1978.00500300038006The task: matching the angles of two partial lines to a numbered fan of lines.
- Treccani, B., & Cubelli, R. (2019). Spatial asymmetries undermine also the short forms of the Judgement of Line Orientation test. Neuropsychology, 33(3), 301-308. https://doi.org/10.1037/neu0000528Each item paired with its left-right mirror image, so the items are balanced for the two sides.
- Collaer, M. L., Reimers, S., & Manning, J. T. (2007). Visuospatial performance on an internet line judgment task and potential hormonal markers: Sex, sexual orientation, and 2D:4D. Archives of Sexual Behavior, 36(2), 177-192. https://doi.org/10.1007/s10508-006-9152-1A line angle judgment task run in a web browser.
Source papers
- Benton AL, Varney NR, Hamsher KdeS (1978). Visuospatial judgment: a clinical test. Archives of Neurology, 35(6):364-367.Paradigm source, Adults
Questions
How long does the Line Angle Matching take?
About 6 to 8 minutes, as listed in the test library.
What device does a participant need?
Untimed test: runs on desktops, laptops and tablets. The browser must be Chrome, Edge, Firefox or Safari.
What scores does it produce?
Percent Correct, Mean Angle Error, Items Correct, Lines Correct, Right-Side Items Correct, Left-Side Items Correct, Median Item Time, Items Answered and Planned Items. Each session is also marked valid, needs review or invalid, with the reason.
How widely is the Line Angle Matching used in research?
95 papers from 2021 to 2025 name it in their title or abstract, up 9% compared with 2016 to 2020. That ranks it 193 of 395 test families in the ConductCognition test census (use grade D). Source: ConductCognition test census 0.14.0, counted 31 October 2026 from OpenAlex and ClinicalTrials.gov.
How much reliability evidence does the Line Angle Matching have?
In the published research, 3 papers report its test-retest reliability and 69 registered clinical studies use it as an outcome (evidence grade C in the ConductCognition test census).
Which settings can a researcher change?
Form (Standard (32 items), Short (16 items)). Settings can be changed on yearly plans; free and pay-as-you-go studies use the standard settings.
Which languages can participants use?
Participants can take this test in English, Spanish, French, German, Italian, Portuguese (Brazil), Chinese (Simplified) and Japanese. English is on every plan, and the other languages come with yearly plans. Have a native speaker read the machine-translated text before launch.
Is this a clinical test?
No. ConductCognition is for research use only. It runs, scores and exports the test; clinical interpretation is outside the platform.
Every test: the full test list.
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