Executive Function
Mixed Practice Task
Also called: interleaving task, interleaved category learning, blocked versus interleaved study
Compare learning from grouped and mixed examples. Participants learn six pattern groups, then classify new patterns.
4-6 minUntimed
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
- 117
- Evidence grade
- D
- Registered clinical studies
- 0
What it measures
Measures how study order affects category learning. Participants study labeled patterns in grouped or mixed order, then sort new patterns into the six groups.
Constructs
- Category learning
- Inductive learning
- Interleaving
- Transfer
Research uses
- Research on study strategies
- Comparing learning schedules
- Research on transfer to new examples
How the paradigm works
Interleaving mixes examples from different categories during study. The Mixed Practice Task compares this order with studying each category in a group, then asks participants to classify new examples. It measures transfer of category learning.
More about the paradigm
Participants study six groups of original line patterns, six examples per group. Three groups are studied together and three are mixed. The session seed assigns the two similar category sets to the study orders, chooses which order comes first and assigns the group numbers. Each pattern appears for 3 seconds, followed by a 500 ms blank. The final test shows 24 new patterns, four per group, with six answer buttons and no feedback. Two separate patterns provide practice with feedback.
The primary score is accuracy after mixed study minus accuracy after grouped study. Positive values favor mixed study. Accuracy for each condition and overall, correct answers, anticipations and completion counts are also reported. Responses under 100 ms count as incorrect. Study time can be set from 2 to 6 seconds.
Kornell and Bjork studied induction from paintings. These original patterns and the shorter session adapt that method. The contrast describes learning in this session; compare it across participants and study conditions. Norms are off.
Scores
- Mixed Study Advantage%
- Mixed accuracy minus grouped accuracy.
- Positive values favor mixed study
- Mixed Study Accuracy%
- Share of new mixed-study patterns classified correctly.
- Higher is better
- Grouped Study Accuracy%
- Share of new grouped-study patterns classified correctly.
- Higher is better
- Overall Accuracy%
- Share of all new patterns classified correctly.
- Chance is 1/6
- Correct Answerscount
- Number of new patterns classified correctly.
- Higher is better
- Anticipationscount
- Final responses under 100 ms, scored as incorrect.
- Quality check
- Patterns Answeredcount
- Final patterns answered in the scored run.
- Compare with the planned count
- Planned Patternscount
- Number of final patterns planned, 24.
- Informational
Use and evidence
117 papers from 2021 to 2025 name this task in their title or abstract, up 26% compared with 2016 to 2020. That ranks it 224 of 582 test families in our census. See the counts for every test.
Show the numbers
| Year | Papers |
|---|---|
| 2025 | 36 |
| 2024 | 21 |
| 2023 | 15 |
| 2022 | 23 |
| 2021 | 22 |
| 2020 | 26 |
| 2019 | 29 |
| 2018 | 14 |
| 2017 | 11 |
| 2016 | 13 |
| 2015 | 4 |
| 2014 | 14 |
| 2013 | 6 |
| 2012 | 7 |
| 2011 | 3 |
| 2010 | 0 |
| 2009 | 1 |
| 2008 | 0 |
| 2007 | 1 |
| 2006 | 1 |
| 2005 | 0 |
| 2004 | 0 |
| 2003 | 0 |
| 2002 | 0 |
| 2001 | 0 |
| 2000 | 0 |
Use grade C
100 to 299 papers from 2021 to 2025.
Evidence grade D
Little published measurement evidence found.
- Papers on test-retest reliability
- 0
- Papers on reliability or validity
- 6
- Registered clinical studies using it as an outcome
- 0
Measured on ConductCognition
Pooled across the studies that feed our platform norms, by device group. A figure needs 50 or more people.
No pooled figure yet.
Note on the counts: includes classroom and motor learning studies.
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 0.39.0, counted 8 November 2026 from OpenAlex and ClinicalTrials.gov.
Task design
The trial sequence as the test runs in ConductCognition.
- Patterns
- Six original categories of line patterns, with jittered vertices. Six study examples and four new test examples per category.
- Study
- 36 labeled patterns, 3 seconds each and a 500 ms blank. Study time can be set from 2 to 6 seconds.
- Order
- Three similar categories studied in a group and three in a mixed sequence. Category sets, group numbers and condition order are counterbalanced from the session seed.
- Test
- 24 new patterns with six group buttons, no response deadline and no feedback. Chance accuracy is 1/6.
- Practice
- Two separate patterns, each studied and classified with feedback.
- Scores
- Mixed minus grouped accuracy, each condition’s accuracy, overall accuracy and completion counts.
An adaptation of category induction from paintings using original line patterns. Compare the study-order contrast across participants; norms are off.
Quality checks
Each session is marked valid, needs review or invalid, with the reason, before you see its scores.
Scored rows: mixed_practice_test of the most complete run, excluding practice. Six choices give chance accuracy of 1/6. Anticipations under 100 ms count as incorrect. Incomplete tests and repeated choices are flagged; very fast responding invalidates. A hidden tab withholds the percentile.
Why these rules
New exemplars test category learning after the two study orders. 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. A hidden tab lets the study, delay or response timers run without the participant, so a percentile is withheld after one.
No percentile. Scores and quality flags only.
Running this test
Settings you can change
| Setting | Standard | Allowed |
|---|---|---|
| Study time per pattern (seconds) | 3 | 2 to 6 |
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
- 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 Mixed Practice Task in a web browser (ConductCognition task version 1.0.0, scoring version 1.0.0; Kornell & Bjork, 2008), with the standard settings (study time per pattern (seconds): 3). The main score was mixed study advantage (mixed accuracy minus grouped accuracy).
ConductCognition versions: task version 1.0.0, scoring version 1.0.0. Every export records the versions each session used, for a methods section.
- Kornell, N., & Bjork, R. A. (2008). Learning Concepts and Categories: Is Spacing the “Enemy of Induction”? Psychological Science, 19(6), 585-592. https://doi.org/10.1111/j.1467-9280.2008.02127.x
Source papers
- Kornell N, Bjork RA (2008). Learning Concepts and Categories: Is Spacing the Enemy of Induction? Psychological Science, 19(6):585-592.Paradigm source, Adults
Questions
How long does the Mixed Practice Task take?
About 4 to 6 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?
Mixed Study Advantage, Mixed Study Accuracy, Grouped Study Accuracy, Overall Accuracy, Correct Answers, Anticipations, Patterns Answered and Planned Patterns. Each session is also marked valid, needs review or invalid, with the reason.
How widely is the Mixed Practice Task used in research?
117 papers from 2021 to 2025 name it in their title or abstract, up 26% compared with 2016 to 2020. That ranks it 224 of 582 test families in the ConductCognition test census (use grade C). Source: ConductCognition test census 0.39.0, counted 8 November 2026 from OpenAlex and ClinicalTrials.gov.
How much reliability evidence does the Mixed Practice Task have?
In the published research, 0 papers report its test-retest reliability and 0 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 settings can a researcher change?
Study time per pattern (seconds) (2 to 6). 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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