Social Cognition
Function Acquisition Speed Task
Also called: function acquisition speed test, FAST, FAST procedure
Measure how fast people learn which key goes with each everyday word when the keys group words that belong together and when they split them, scored as a difference in learning speed.
4-5 minTimed: desktop or laptop with a mouse or trackpad
Free to start: 10 free participants per account, then $0.99 per participant for academic research, or any yearly plan. Try it here first, with no account.
- Papers, 2021 to 2025
- 10
- Evidence grade
- D
- Registered clinical studies
- 2
What it measures
Measures how fast people learn which key goes with each of four everyday words when the keys group words that belong together, such as hammer and nail, and when they split them. The keys are learned by trial and error from feedback, and the main score is the difference in learning speed between the two parts.
Constructs
- Stimulus relatedness
- Implicit learning of response functions
- Associative strength
Research uses
- Relational frame theory and contextual behavioral science research
- Social cognition and attitude research at the group level
- Method studies of implicit measures
How the paradigm works
The Function Acquisition Speed Task measures how fast people learn which key goes with each word when the keys group words that belong together and when they split them. It follows the Function Acquisition Speed Test (FAST) of O'Reilly, Roche, Ruiz, Tyndall and Gavin (2012), in the fixed blocks of 50 trials and the slope score of Cummins, Roche, Tyndall and Cartwright (2018). One word appears at a time in the middle of the screen; the participant presses D or K within 3 seconds and then sees Correct or Wrong for 500 ms, and a missed answer counts as wrong. No rule is given: the key for each word is learned from the feedback alone. A 500 ms blank comes before each word.
More about the paradigm
The words are two pairs of everyday things used together, hammer and nail, and spoon and fork, written in each of the eight languages and neutral in meaning. A practice block of 10 trials teaches the keys of one word of each pair, the anchors, alone. In the consistent block each anchor's partner shares its key, so the words that belong together share a key; in the inconsistent block each partner shares the other anchor's key. The anchors keep their keys throughout. Which anchor takes which key, and which block comes first, are drawn from the session's seed, and the screen before the second block says only that some keys may have changed. Each block shows the four words in shuffled cycles of four, 50 trials in all.
The main score, the FAST score, is the slope of the consistent block's cumulative record (right answers counted against cumulative response time, in right answers per minute) minus the inconsistent block's. Positive scores mean the keys were learned faster when they grouped the words that belong together. The task also reports each block's slope, the rate fluency differential that Watters, Cummins and Roche (2023) proposed (right minus wrong answers per minute of each block, consistent minus inconsistent), because fast guessing can give a steep slope, and each block's accuracy and response time. Answers under 100 ms are counted as anticipations. In the first study, 13 of 18 participants learned faster in the consistent block (O'Reilly et al., 2012), and Cummins and colleagues (2018) found FAST scores rose with how strongly the words had been related. A FAST score is a research measure for group comparisons and says little about one person. Scores support research and do not diagnose.
Scores
- FAST Scorecorrect/min
- Slope of the consistent block's cumulative record minus the inconsistent block's, in right answers per minute of response time.
- Positive values mean the keys were learned faster when they grouped the words that belong together; not better or worse
- Consistent Block Slopecorrect/min
- Regression slope of cumulative right answers on cumulative response time in the block where the words that belong together share a key.
- Higher is faster learning
- Inconsistent Block Slopecorrect/min
- Regression slope of cumulative right answers on cumulative response time in the block where the words that belong together have different keys.
- Higher is faster learning
- Fluency Differentialcorrect/min
- Right minus wrong answers per minute of block time, blanks and feedback included, consistent block minus inconsistent block.
- Positive values mean more fluent answers in the consistent block
- Consistent Accuracy%
- Share of the consistent block's trials answered with the right key in time.
- Higher is better
- Inconsistent Accuracy%
- Share of the inconsistent block's trials answered with the right key in time.
- Higher is better
- Consistent Response Timems
- Mean time of the consistent block's right answers, from 100 ms.
- Lower is faster
- Inconsistent Response Timems
- Mean time of the inconsistent block's right answers, from 100 ms.
- Lower is faster
- Practice Accuracy%
- Share of the 10 practice trials answered with the right key in time.
- Informational
- Missed Trialscount
- Test trials with no key within 3,000 ms.
- Above 0 is flagged for review
- Anticipationscount
- Test answers under 100 ms after the word appeared.
- Quality check
- Block Ordercount
- 1 when the consistent block came first, 2 when the inconsistent block did, drawn from the session's seed.
- Informational
- Planned Test Trialstrials
- Test trials in two blocks of 50.
- Informational
- Total Test Trialstrials
- Test trials in the scored run.
- Fewer than planned is flagged for review
Use and evidence
10 papers from 2021 to 2025 name this task in their title or abstract. That ranks it 453 of 495 test families in our census. See the counts for every test.
Show the numbers
| Year | Papers |
|---|---|
| 2025 | 4 |
| 2024 | 2 |
| 2023 | 3 |
| 2022 | 1 |
| 2021 | 0 |
| 2020 | 1 |
| 2019 | 1 |
| 2018 | 2 |
| 2017 | 2 |
| 2016 | 1 |
| 2015 | 0 |
| 2014 | 1 |
| 2013 | 3 |
| 2012 | 2 |
| 2011 | 0 |
| 2010 | 0 |
| 2009 | 0 |
| 2008 | 0 |
| 2007 | 0 |
| 2006 | 0 |
| 2005 | 0 |
| 2004 | 0 |
| 2003 | 0 |
| 2002 | 0 |
| 2001 | 0 |
| 2000 | 0 |
Use grade E
Fewer than 30 papers from 2021 to 2025.
Evidence grade D
Little published measurement evidence found.
- Papers on test-retest reliability
- 1
- Papers on reliability or validity
- 4
- Registered clinical studies using it as an outcome
- 2
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 0.22.0, counted 2 November 2026 from OpenAlex and ClinicalTrials.gov.
Task design
The trial sequence as the test runs in ConductCognition.
- Trials
- One word in the middle of the panel until D or K or 3,000 ms, then Correct or Wrong for 500 ms; a missed answer counts as wrong. A 500 ms blank comes before each word, and no rule is shown.
- Words
- Two pairs of everyday things used together, hammer and nail and spoon and fork, written in each app language. In English their Glasgow Norms valences are 4.6 to 5.5 of 9, so neither pair is good or bad.
- Practice
- 10 trials with one word of each pair, the anchors, alone, each with its own key.
- Blocks
- 2 blocks of 50 trials, the four words in shuffled cycles of four. Consistent: each anchor's partner shares its key. Inconsistent: each partner shares the other anchor's key. The anchors keep their keys, and which block comes first is drawn from the seed.
- Scoring
- Each block's slope: right answers against cumulative response time, in answers per minute. The FAST score is the consistent slope minus the inconsistent slope; the fluency differential compares right minus wrong answers per minute.
O'Reilly and colleagues (2012) ran each block until 10 right answers in a row, with baseline blocks before and after, and later studies fixed the blocks at 50 trials, mostly with no practice. Here a short practice with the two anchors comes first, so each test block teaches the keys of their partners, and the words are everyday pairs written in each language. Compare scores within a study.
Quality checks
Each session is marked valid, needs review or invalid, with the reason, before you see its scores.
Scored rows: function_acquisition_trial from the scored run, D or K for each word within 3,000 ms (chance 50%, each key is right on about half the trials), learned from feedback, correctness from the key pressed. Below chance invalidates and not above chance is flagged. One key on 90% of answered trials invalidates when accuracy is not above chance. A run short of its planned trials is flagged. Missed responses and responses under 100 ms follow the timed-test rule.
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). Missed responses and responses under 100 ms keep the platform's timed-test rule: more than max(3, 25%) missed responses or more than max(2, 20%) responses under 100 ms invalidate, and any is flagged. A response under 100 ms cannot be a reaction to the stimulus. The first answers to each new word are guesses by design, so accuracy is judged over the whole run, where learning makes it well above chance.
No percentile. Scores and quality flags only.
Running this test
Settings you can change
This test runs with fixed settings.
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Devices and languages
- Timed test: participants need a desktop or laptop with a mouse or trackpad. Participant devices
- Languages: English, Spanish, French, German, Italian, Portuguese (Brazil), Chinese (Simplified) and Japanese.
- Available on: Every plan, including the free plan.
- 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
Participants completed the Function Acquisition Speed Task in a web browser (ConductCognition task version 1.0.0, scoring version 1.0.0; O'Reilly, Roche, Ruiz, Tyndall & Gavin, 2012). The main score was FAST score (slope of the consistent block's cumulative record minus the inconsistent block's, in right answers per minute of response time).
ConductCognition versions: task version 1.0.0, scoring version 1.0.0. Every export records the versions each session used, for a methods section.
- O'Reilly, A., Roche, B., Ruiz, M., Tyndall, I., & Gavin, A. (2012). The Function Acquisition Speed Test (FAST): A behavior analytic implicit test for assessing stimulus relations. The Psychological Record, 62(3), 507-528. https://doi.org/10.1007/BF03395817The test: key presses for words learned from feedback, in a block that fits a trained relation and a block that does not, compared by learning speed.
- Cummins, J., Roche, B., Tyndall, I., & Cartwright, A. (2018). The relationship between differential stimulus relatedness and implicit measure effect sizes. Journal of the Experimental Analysis of Behavior, 110(1), 24-38. https://doi.org/10.1002/jeab.437Blocks of 50 trials scored by the slope of a cumulative record, and FAST scores that rose with how strongly the words had been related.
- Watters, A., Cummins, J., & Roche, B. (2023). How to build and how not to build an implicit measure in behavior analysis: A case study using the Function Acquisition Speed Test. Perspectives on Behavior Science, 46(3-4), 459-492. https://doi.org/10.1007/s40614-023-00387-wHow the test is built: two pairs at once, feedback after every answer, 50-trial blocks, and the rate fluency differential.
Source papers
- O'Reilly A, Roche B, Ruiz M, Tyndall I, Gavin A (2012). The Function Acquisition Speed Test (FAST): A behavior analytic implicit test for assessing stimulus relations. The Psychological Record, 62(3):507-528.Paradigm source, Adults
- Cummins J, Roche B, Tyndall I, Cartwright A (2018). The relationship between differential stimulus relatedness and implicit measure effect sizes. Journal of the Experimental Analysis of Behavior, 110(1):24-38.Paradigm source, Adults
- No normative data for this task.Paradigm source, N/A
Questions
How long does the Function Acquisition Speed Task take?
About 4 to 5 minutes, as listed in the test library.
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?
FAST Score, Consistent Block Slope, Inconsistent Block Slope, Fluency Differential, Consistent Accuracy, Inconsistent Accuracy, Consistent Response Time, Inconsistent Response Time, Practice Accuracy, Missed Trials, Anticipations, Block Order, Planned Test Trials and Total Test Trials. Each session is also marked valid, needs review or invalid, with the reason.
How widely is the Function Acquisition Speed Task used in research?
10 papers from 2021 to 2025 name it in their title or abstract. That ranks it 453 of 495 test families in the ConductCognition test census (use grade E). Source: ConductCognition test census 0.22.0, counted 2 November 2026 from OpenAlex and ClinicalTrials.gov.
How much reliability evidence does the Function Acquisition Speed Task have?
In the published research, 1 paper reports its test-retest reliability and 2 registered clinical studies use it as an outcome (evidence grade D in the ConductCognition test census).
Does it report a percentile?
No. Scores and quality flags only.
Which languages can participants use?
Participants can take this test in English, Spanish, French, German, Italian, Portuguese (Brazil), Chinese (Simplified) and Japanese, with its words in the same language. 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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