How long does the Lexical Decision Task take?
About 3 to 5 minutes, as listed in the test library.
Language
Lexical Decision Task
Also called: LDT, word-nonword task
Measure how quickly people recognize written words, with common and rare words and pronounceable nonwords.
Useful for reading, language, bilingualism, aging, and psycholinguistics research.
Run it with participant credits from $0.99 per participant, or any yearly plan. Preview any test free after you sign up.
Language3-5 minTimed: desktop or laptop with a mouse or trackpadPaid plans and pay as you go
castle
rendam
F
J
Word or not a word? Answer with F or J
What the participant sees
One trial, screen by screen, with the timings the test uses.
500 ms
A cross
Until a key press, up to 2,000 ms
A letter string
- ForJ
- Word or not a word
Which of F and J means word is counterbalanced across sessions and saved with each answer.
Example stimuli
Taken from the test's own stimuli.
Common word
Zipf frequency 4.53
Rare word
Zipf frequency 2.78
Nonword
Made from "random"
Session structure
Practice
8 trials
Common words
20 trials
Rare words
20 trials
Nonwords
40 trials
Scores and how they are computed
RT means response time. Mean RTs use correct responses at or after 100 ms.
- Word RTms
- Mean correct RT to words.
- Lower is faster
- Word Accuracyproportion
- Share of words answered as words.
- Higher is better
- Nonword Accuracyproportion
- Share of nonwords answered as not words.
- Higher is better
- Frequency Effectms
- Rare-word minus common-word mean correct RT.
- Positive values mean common words were recognized faster
- Nonword RTms
- Mean response time of correct answers to nonwords.
- Lower is faster
- Common-Word RTms
- Mean correct response time to common words.
- Lower is faster
- Rare-Word RTms
- Mean correct response time to rare words.
- Lower is faster
- Accuracyproportion
- Share of all test trials answered correctly.
- Higher is better
Example dataOne simulated session, scored by the code that scores your study's sessions.
- Common words567.6 ms
- Rare words644.9 ms
- Nonwords671.1 ms
Mean correct response time (ms)
- Frequency effect
- 77.3 ms
- Word accuracy
- 92.5%
- Nonword accuracy
- 97.5%
| Common words, mean correct response time | 567.6 ms |
|---|---|
| Rare words, mean correct response time | 644.9 ms |
| Nonwords, mean correct response time | 671.1 ms |
What this task measures
Measures how quickly people recognize written words. A string of letters appears and participants decide whether it is an English word, pressing F or J. Half the strings are common or rare words and half are pronounceable nonwords.
Core constructs
- Visual word recognition
- Lexical access
- Processing speed
Research fit
- Reading and language research
- Bilingualism and second-language research
- Aging and psycholinguistics studies
Paradigm overview
The lexical decision task measures how quickly people recognize written words. A string of letters appears in the middle of the screen and participants decide whether it is an English word, pressing one key for a word and the other for a nonword. Which of F and J means word is drawn from the session's random seed and recorded.
Each trial starts with a 500 ms cross, and the letters stay until a response or 2,000 ms. The standard 80 trials hold 20 sets drawn at random from 40. Each set is a common word (Zipf frequency 4.5 or higher), a rare but familiar word (Zipf 2 to 3) and two pronounceable nonwords, all of one length (4 to 7 letters). Nonwords change one or two letters of a real word and are checked against English word lists. Trials run in a recorded random order with no more than three words or three nonwords in a row, after 8 practice trials with feedback.
The main score is the mean response time of correct word answers. The frequency effect is the rare-word minus common-word mean correct response time; positive values mean common words were recognized faster. Words were chosen by fixed rules from the Glasgow Norms and OpenSubtitles word frequencies. The words are English, and sessions run in other languages are flagged for review.
Task design as built
The trial sequence participants see, as the test runs in ConductCognition. Settings a researcher can change are listed below.
- Trial
- A 500 ms cross, then a letter string until a response or 2,000 ms.
- Keys
- F and J; which key means word is counterbalanced across sessions and saved.
- Items
- 80 trials standard (40 to 160), in sets of a common word, a rare word and two nonwords of one length.
- Words
- Common words Zipf 4.5 or higher and rare words Zipf 2 to 3, chosen by fixed rules from openly licensed norms.
- Nonwords
- Pronounceable strings made by changing one or two letters of real words, checked against English word lists.
- Order
- Random order from the session's seed, with no more than three words or three nonwords in a row.
- Practice
- 8 trials with feedback.
The words are English. Sessions run in other languages are flagged for review.
Data you get
Every response is saved as it happens. Download scores for all plans, and every trial on yearly plans or with participant credits.
Trial columns for this test
- phase
- practice or test. Scores use test rows.
- trial_number
- Order of the trial within its phase.
- random_seed
- Seed of the session's trial order, to rebuild it.
- letter_string
- The string shown.
- lexicality
- word or nonword.
- frequency_band
- high (common) or low (rare) for words.
- zipf
- Word frequency on the Zipf scale.
- base_word
- The real word a nonword was made from.
- word_key
- The key that meant word in this session, f or j.
- correct_response
- The right key for the trial.
- response
- The key pressed, empty when none.
- rt
- Response time in ms from the moment the screen to answer appeared.
- correct
- Whether the key pressed was the right one.
- timed_out
- No key before the time limit.
- anticipation
- A key under 100 ms, too fast to be a response.
Columns in every export
- participant_id
- Short participant code, the same in every file of the study.
- external_id
- Your own participant ID, when you add one.
- test_version
- Task version the session ran.
- scoring_version
- Scoring version the scores came from.
- customization_status
- standard, or scored_modified when the study changed a setting.
- configuration_json
- The task settings the session ran with.
- is_valid
- The session's quality status (scores file).
- quality_primary_reason
- The main reason when a session needs review or is invalid (scores file).
- started_at
- When the session started (scores file).
- completed_at
- When the session ended (scores file).
Quality checks
Each session is marked valid, needs review or invalid, with the reason.
Scored rows: lexical_decision_test from the scored run, F or J for word or nonword (chance 50%, half the strings are words) within 2,000 ms, correctness from the key for the string. Below chance invalidates and not above chance is flagged. One key on 90% of answers invalidates when accuracy is not above chance. Missed responses and responses under 100 ms follow the timed-test rule. A session run in a language other than English is flagged for review.
No percentile. Scores and quality flags only.
Running this test
Settings you can change
| Setting | Standard | Allowed |
|---|---|---|
| Test trials | 80 | 40 to 160 |
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
- Timed test: participants need a desktop or laptop with a mouse or trackpad. Participant devices
- Task text: English and Italian.
- Available on: Paid plans and pay as you go.
- No percentile. Scores and quality flags only. How norms work
- Recruiting online? See the setup guides for Prolific, Sona Systems, CloudResearch Connect and Qualtrics.
Cite and describe
Methods text, with the standard settings
Participants completed the Lexical Decision Task in a web browser (ConductCognition task version 1.0.0, scoring version 1.0.0; Meyer & Schvaneveldt, 1971), with the standard settings (test trials: 80). Word RT was computed as the mean response time of correct answers to words. Mean response times used correct responses at or after 100 ms.
ConductCognition versions: task version 1.0.0, scoring version 1.0.0. Every export records the versions each session used, for a methods section.
- Meyer, D. E., & Schvaneveldt, R. W. (1971). Facilitation in recognizing pairs of words: Evidence of a dependence between retrieval operations. Journal of Experimental Psychology, 90(2), 227-234. https://doi.org/10.1037/h0031564
- Balota, D. A., Yap, M. J., Hutchison, K. A., Cortese, M. J., Kessler, B., Loftis, B., Neely, J. H., Nelson, D. L., Simpson, G. B., & Treiman, R. (2007). The English Lexicon Project. Behavior Research Methods, 39(3), 445-459. https://doi.org/10.3758/BF03193014
Source papers
Meyer DE, Schvaneveldt RW (1971). Facilitation in recognizing pairs of words: evidence of a dependence between retrieval operations. Journal of Experimental Psychology, 90(2):227-234.
Paradigm sourceAdults
Balota DA, Yap MJ, Hutchison KA, et al. (2007). The English Lexicon Project. Behavior Research Methods, 39(3):445-459.
Paradigm sourceAdults
Research FAQ
Common questions about this online cognitive test
What device does a participant need?
Timed test: participants need a desktop or laptop with a mouse or trackpad. The browser must be Chrome, Edge, Firefox or Safari.
What scores does it produce?
Word RT, Word Accuracy, Nonword Accuracy, Frequency Effect, Nonword RT, Common-Word RT, Rare-Word RT and Accuracy. Each session is also marked valid, needs review or invalid, with the reason.
How is word RT computed?
Mean correct RT to words.
How is the frequency effect computed?
Rare-word minus common-word mean correct RT.
Does it report a percentile?
No. Scores and quality flags only.
Which settings can a researcher change?
Test trials (40 to 160). Settings can be changed on yearly plans; free and pay-as-you-go studies use the standard settings.
Which languages can participants use?
The test's own text is in English and Italian. Italian participant pages come with yearly plans.
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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