Language
Vocabulary Test
Also called: synonym vocabulary test, multiple-choice vocabulary test, verbal ability test
Measure English vocabulary with multiple-choice synonym items that run from common to rare words.
5-8 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
- 550
- Evidence grade
- A
- Registered clinical studies
- 198
What it measures
Measures English vocabulary knowledge. Each item shows a word and five others, and participants choose the one that means the same. The 40 items run from common to rare words in four frequency bands.
Constructs
- Vocabulary knowledge
- Crystallized intelligence
- Verbal ability
Research uses
- Language and reading research
- Verbal ability as a covariate in cognitive studies
- Within-study group comparison
How the paradigm works
The vocabulary test measures how many English words a person knows. Each item shows a word with five words below it, and participants choose the one that means the same or nearly the same. The format follows the classic multiple-choice vocabulary test of verbal ability (Thorndike 1942), whose ten-item General Social Survey version, Wordsum, is widely used in survey research.
More about the paradigm
The 40 items were written for this task; no published vocabulary test is used. They come in four frequency bands of 10, from common words to rare ones, judged by word frequency in the Google Books Ngram English corpus, and every participant sees them in the same order, easiest first. The answer is always a well-known word, and the other four words match it in part of speech and length, so knowing the target word is what helps. The answer is in each of the five positions equally often. Each item stays on screen for up to 30 seconds, with no countdown, after 3 practice items with feedback. A 20-item short form uses the odd-numbered items of each band. The items are English.
The main score is accuracy: the proportion of items answered correctly, with an unanswered item counted as wrong. Accuracy in each frequency band and the median time to a correct answer are also reported. Scores support research and do not diagnose.
Scores
- Accuracy%
- Share of items answered correctly; an unanswered item counts as wrong.
- Higher is better
- Items Correctcount
- Items answered correctly.
- Higher is better
- Accuracy, Common Words%
- Share of the common-word items answered correctly.
- Higher is better
- Accuracy, Moderate Words%
- Share of the moderately common items answered correctly.
- Higher is better
- Accuracy, Uncommon Words%
- Share of the uncommon-word items answered correctly.
- Higher is better
- Accuracy, Rare Words%
- Share of the rare-word items answered correctly.
- Higher is better
- Median Correct Timems
- Median time to a correct answer; answers under 100 ms are left out.
- Lower is faster
- Unanswered Itemscount
- Items whose time ran out without an answer.
- Context for accuracy
Use and evidence
550 papers from 2021 to 2025 name this task in their title or abstract, down 22% compared with 2016 to 2020. That ranks it 45 of 395 test families in our census. See the counts for every test.
Show the numbers
| Year | Papers |
|---|---|
| 2025 | 120 |
| 2024 | 90 |
| 2023 | 111 |
| 2022 | 119 |
| 2021 | 110 |
| 2020 | 133 |
| 2019 | 131 |
| 2018 | 135 |
| 2017 | 161 |
| 2016 | 143 |
| 2015 | 104 |
| 2014 | 122 |
| 2013 | 102 |
| 2012 | 111 |
| 2011 | 112 |
| 2010 | 118 |
| 2009 | 67 |
| 2008 | 76 |
| 2007 | 56 |
| 2006 | 74 |
| 2005 | 38 |
| 2004 | 44 |
| 2003 | 42 |
| 2002 | 33 |
| 2001 | 33 |
| 2000 | 45 |
Use grade B
300 to 999 papers from 2021 to 2025.
Evidence grade A
At least 25 papers report its test-retest reliability and at least 25 registered clinical studies use it as an outcome.
- Papers on test-retest reliability
- 49
- Papers on reliability or validity
- 503
- Registered clinical studies using it as an outcome
- 198
Note on the counts: includes commercial vocabulary tests.
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.
- Items
- 40 target words in four frequency bands of 10 (common, moderate, uncommon and rare), judged by Zipf frequency in the Google Books Ngram English 2019 corpus.
- Answer
- A target word above five answer buttons; one of the five words means the same or nearly the same.
- Order
- The same fixed order for everyone, from the most to the least frequent target. The answer is in each of the five positions equally often.
- Time
- Each item stays on screen for up to 30 seconds (standard; 15 to 60), with no countdown. An unanswered item counts as wrong.
- Practice
- 3 items with feedback for 2,500 ms.
- Short form
- 20 items: the odd-numbered 5 of each band, in the same order.
The items were written for this task; no published vocabulary test is used. The items are English.
Quality checks
Each session is marked valid, needs review or invalid, with the reason, before you see its scores.
Scored rows: vocabulary_test from the scored run, one answer of five per item. Accuracy significantly below chance (one in five) invalidates and accuracy not above chance is flagged. Answers under 200 ms on at least half of the answered items invalidate. More than max(3, 25%) items left unanswered invalidate and any is flagged. The same answer position on 90% of at least 12 answers, with accuracy not above chance, invalidates. A session run in another language is flagged. A hidden tab withholds the percentile.
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). The answer is in each of the five positions equally often. Each item allows a generous time, so an item left unanswered means the participant was not taking part; more than max(3, 25%) such items invalidate, as in the platform's timed-test rule, and any is flagged. 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. The word lists are English. A session run in another language shows English words to a participant who may not read English fluently, so it is flagged for review. Another tab can be used to look up a word, so a percentile is withheld after a hidden tab.
Running this test
Settings you can change
| Setting | Standard | Allowed |
|---|---|---|
| Test form | Full, 40 items (standard) | Full, 40 items (standard), Short, 20 items |
| Time per item (seconds) | 30 | 15 to 60 |
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, tablets and phones. Participant devices
- Instructions and screens: English, Spanish, French, German, Italian, Portuguese (Brazil), Chinese (Simplified) and Japanese. Words and sentences: English.
- 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 Vocabulary Test in a web browser (ConductCognition task version 1.0.0, scoring version 1.0.0; Thorndike, 1942), with the standard settings (test form: Full, 40 items; time per item (seconds): 30). The main score was accuracy (share of items answered correctly; an unanswered item counts as wrong).
ConductCognition versions: task version 1.0.0, scoring version 1.0.0. Every export records the versions each session used, for a methods section.
- Thorndike, R. L. (1942). Two screening tests of verbal intelligence. Journal of Applied Psychology, 26(2), 128-135. https://doi.org/10.1037/h0060053
- Cor, M. K., Haertel, E., Krosnick, J. A., & Malhotra, N. (2012). Improving ability measurement in surveys by following the principles of IRT: The Wordsum vocabulary test in the General Social Survey. Social Science Research, 41(5), 1003-1016. https://doi.org/10.1016/j.ssresearch.2012.05.007
Source papers
- Thorndike RL (1942). Two screening tests of verbal intelligence. Journal of Applied Psychology, 26(2):128-135.Paradigm source, Adults
- Cor MK, Haertel E, Krosnick JA, Malhotra N (2012). Improving ability measurement in surveys by following the principles of IRT: the Wordsum vocabulary test in the General Social Survey. Social Science Research, 41(5):1003-1016.Paradigm source, Adults
Questions
How long does the Vocabulary Test take?
About 5 to 8 minutes, as listed in the test library.
What device does a participant need?
Untimed test: runs on desktops, laptops, tablets and phones. The browser must be Chrome, Edge, Firefox or Safari.
What scores does it produce?
Accuracy, Items Correct, Accuracy, Common Words, Accuracy, Moderate Words, Accuracy, Uncommon Words, Accuracy, Rare Words, Median Correct Time and Unanswered Items. Each session is also marked valid, needs review or invalid, with the reason.
How widely is the Vocabulary Test used in research?
550 papers from 2021 to 2025 name it in their title or abstract, down 22% compared with 2016 to 2020. That ranks it 45 of 395 test families in the ConductCognition test census (use grade B). Source: ConductCognition test census 0.14.0, counted 31 October 2026 from OpenAlex and ClinicalTrials.gov.
How much reliability evidence does the Vocabulary Test have?
In the published research, 49 papers report its test-retest reliability and 198 registered clinical studies use it as an outcome (evidence grade A in the ConductCognition test census).
Which settings can a researcher change?
Test form (Full, 40 items (standard), Short, 20 items) and time per item (seconds) (15 to 60). Settings can be changed on yearly plans; free and pay-as-you-go studies use the standard settings.
Which languages can participants use?
The instructions and screens are in English, Spanish, French, German, Italian, Portuguese (Brazil), Chinese (Simplified) and Japanese. The words and sentences stay in English, so sessions in other languages are flagged for review. 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.
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