GITNUXREPORT 2026

Knowledge Retention Statistics

Without review we forget quickly, but spaced repetition locks in knowledge.

Min-ji Park

Research Analyst focused on sustainability and consumer trends.

First published: Feb 13, 2026

Our Commitment to Accuracy

Rigorous fact-checking · Reputable sources · Regular updatesLearn more

Statistic 1

Multimedia learning with images retains 65% vs 45% text-only, Mayer principle

Statistic 2

Dual-coding theory: visuals + words retain 89% vs 72% single mode

Statistic 3

Elaborative encoding with examples boosts retention 40%

Statistic 4

Mnemonics like method of loci retain 70% names after 1 month

Statistic 5

Concrete examples in lessons retain 68% vs 39% abstract

Statistic 6

Storytelling framing retains 22% more info than facts alone

Statistic 7

Gamification with badges increases retention 30% in e-learning

Statistic 8

Background music distracts, reducing retention by 15% for verbal tasks

Statistic 9

Contextual cues at retrieval match encoding boost retention 50%

Statistic 10

Social context encoding retains 35% more with peers present

Statistic 11

Scent cues matching study/test retain 15% more

Statistic 12

Pomodoro technique (25 min study) retains 28% more than marathon

Statistic 13

Feynman technique explaining simply retains 50% deeper understanding

Statistic 14

Mind mapping visuals retain 32% more hierarchical info

Statistic 15

Interleaved topics retain 76% vs 42% blocked practice

Statistic 16

Augmented reality learning retains 75% vs 40% traditional

Statistic 17

Peer teaching retains 90% vs 50% passive listening

Statistic 18

Error-based learning retains 40% more robust knowledge

Statistic 19

Daylight exposure during study boosts retention 20%

Statistic 20

In Ebbinghaus's classic experiment, individuals forget approximately 58% of newly learned nonsense syllables within 20 minutes without review

Statistic 21

After one hour, retention drops to about 44% for the same nonsense syllables in Ebbinghaus's study

Statistic 22

By the end of 24 hours, only 33% of nonsense syllables are retained without reinforcement, per Ebbinghaus

Statistic 23

After 6 days, retention falls to 25% for rote-learned material in Ebbinghaus's curve

Statistic 24

One month post-learning, nonsense syllable retention is around 21% without spaced review

Statistic 25

Modern replications show 42% forgetting of factual knowledge within 1 day in medical students

Statistic 26

70% of lecture content is forgotten within 24 hours by college students

Statistic 27

Half-life of knowledge in corporate training is 5 years, leading to 20% annual decay

Statistic 28

Surgeons forget 30% of surgical knowledge within 1 year post-training

Statistic 29

Language learners forget 50% of vocabulary in 2 weeks without practice

Statistic 30

Interference from similar info causes 35% forgetting in paired associates

Statistic 31

Retroactive interference reduces retention by 28% post new learning

Statistic 32

Emotional arousal slows forgetting by 20% for central details

Statistic 33

Hyperthymesia cases retain 99.99% autobiographical events

Statistic 34

Alcohol intoxication at encoding causes 40% steeper forgetting curve

Statistic 35

Age-related forgetting accelerates: 20% per decade after 30 for episodic memory

Statistic 36

Stress hormones like cortisol increase forgetting by 25% short-term

Statistic 37

Bilinguals forget L2 words 15% faster than L1 without use

Statistic 38

Video game skills decay 10% per week without play

Statistic 39

Musical instrument proficiency forgets 30% in 3 months idle

Statistic 40

56% of new hires forget training in 1 hour, 88% in 1 week without spacing

Statistic 41

Physicians forget 58% of knowledge in first year residency

Statistic 42

Software devs forget 80% API docs in 2 days

Statistic 43

Consumers forget 90% ad content in 3 days

Statistic 44

Students forget 65% class material by exam time

Statistic 45

Teams forget project procedures 50% in 6 months

Statistic 46

Artists forget techniques 35% after 1 month break

Statistic 47

Spaced repetition at 1-day interval boosts retention to 80% after 1 week vs 50% massed

Statistic 48

Expanding intervals (1,3,7 days) yield 90% retention after 30 days, per Cepeda study

Statistic 49

Leitner system with 5 boxes increases flashcard retention by 200% over linear review

Statistic 50

Spacing factor of 2.5 in Anki software retains 95% of items after 1 year

Statistic 51

Three spaced sessions over a week retain 65% vs 30% single session after 1 month

Statistic 52

Optimal spacing lag of 10-30% of test interval maximizes retention by 40%

Statistic 53

Daily micro-sessions of 10 min spaced over month retain 85% vs 55% cramming

Statistic 54

Bilingual spacing training retains 75% vocabulary after 6 months

Statistic 55

Interleaved practice with spacing boosts math retention by 43% after 1 week

Statistic 56

SuperMemo algorithm SM-18 achieves 97% retention with adaptive spacing

Statistic 57

Spacing with 1-week gap retains 82% vs 55% immediate for vocab

Statistic 58

Hyperbolic spacing (days 1,2,4,8) achieves 93% after 2 months

Statistic 59

App-based spacing retains 78% languages after 1 year, Duolingo study

Statistic 60

Review at 35% fluency threshold optimizes retention to 96%

Statistic 61

Clustered spacing over 3 days retains 70% vs 45% distributed poorly

Statistic 62

Long lag spacing (1 month) retains 60% better for durable skills

Statistic 63

Mixed modality spacing retains 85% cross-sensory info

Statistic 64

Corporate spaced training retains 50% more after 6 months

Statistic 65

FSRS algorithm improves Anki retention to 98% long-term

Statistic 66

Spacing reduces overconfidence, improving retention accuracy 25%

Statistic 67

Spaced reviews every 10 days retain 91% vocab after 1 year

Statistic 68

4 spaced exposures needed for 90% retention threshold

Statistic 69

Adaptive spacing in RemNote retains 94% user data

Statistic 70

Short sessions spaced retain 2x motor skills vs massed

Statistic 71

Sleep after learning consolidates memory, boosting retention by 20-40% next day

Statistic 72

90 minutes of sleep post-training retains 85% vs 60% wakefulness, Stickgold study

Statistic 73

REM sleep enhances procedural memory retention by 30%

Statistic 74

Napping 60-90 min post-learning improves factual recall by 35%

Statistic 75

Sleep spindles correlate with 2x better retention of word pairs

Statistic 76

Chronic sleep deprivation reduces retention by 40% in hippocampus-dependent tasks

Statistic 77

Daytime naps retain 70% of spatial info vs 50% no nap

Statistic 78

Overnight sleep stabilizes memories, reducing forgetting by 25%

Statistic 79

Slow-wave sleep boosts declarative memory retention by 50%

Statistic 80

Caffeine before sleep impairs retention by 15-20%

Statistic 81

Exercise before learning increases retention by 20% via BDNF

Statistic 82

Sleep before testing consolidates, boosting recall 22%

Statistic 83

Circadian rhythm peaks retention 15% higher morning vs afternoon

Statistic 84

Meditation post-learning enhances retention 16% via mindfulness

Statistic 85

Hydration levels: Dehydration reduces retention 20%

Statistic 86

Omega-3 intake improves retention 25% in elderly

Statistic 87

Aerobic exercise post-study retains 30% more episodic memory

Statistic 88

Blue light exposure pre-sleep reduces retention 12%

Statistic 89

Hormonal cycle: Luteal phase retains 10% more verbal memory

Statistic 90

Fasting 16 hours impairs retention 18% short-term

Statistic 91

Music during sleep cues retain 20% better targeted memories

Statistic 92

Retrieval practice twice daily retains 92% of facts after 7 days vs 60% passive

Statistic 93

Testing effect doubles long-term retention (76% vs 36%) after 1 week, Roediger study

Statistic 94

Self-testing improves retention by 50% over restudying for text material

Statistic 95

Frequent low-stakes quizzes retain 80% after semester vs 50% no quizzes

Statistic 96

Generation effect from recall boosts retention 30% higher than recognition

Statistic 97

Distributed practice with tests retains 63% after 3 months vs 28% massed

Statistic 98

Flashcard testing with confidence ratings retains 88% after 1 month

Statistic 99

Effortful retrieval strengthens memory twice as much as easy recall

Statistic 100

Pre-testing before learning boosts final retention by 25%

Statistic 101

Repeated testing over 4 sessions retains 90% vs 50% single test

Statistic 102

Free recall testing retains 56% vs 40% recognition after delay

Statistic 103

Dozens of tests over semester boost retention 2.5x final exam

Statistic 104

Elaborative interrogation during tests retains 40% more concepts

Statistic 105

Calibration training with tests improves retention judgment 35%

Statistic 106

Backward recall chaining retains sequences 50% better

Statistic 107

Testing with errors strengthens memory 30% more than correct

Statistic 108

Collaborative testing retains 25% more in groups vs solo

Statistic 109

Immediate feedback post-test retains 90% vs 70% delayed

Statistic 110

High-desirability tests retain emotional content 45% better

Statistic 111

Retrieval-induced forgetting protects key memories, retaining 80%

1/111

Sources

Trusted by 500+ publications

+497

Imagine your brain as a leaky bucket: within 24 hours of learning something new, studies show we can lose up to 70% of it, but by strategically patching those leaks with proven methods like spaced repetition, we can boost long-term retention to over 90%.

Key Takeaways

In Ebbinghaus's classic experiment, individuals forget approximately 58% of newly learned nonsense syllables within 20 minutes without review
After one hour, retention drops to about 44% for the same nonsense syllables in Ebbinghaus's study
By the end of 24 hours, only 33% of nonsense syllables are retained without reinforcement, per Ebbinghaus
Spaced repetition at 1-day interval boosts retention to 80% after 1 week vs 50% massed
Expanding intervals (1,3,7 days) yield 90% retention after 30 days, per Cepeda study
Leitner system with 5 boxes increases flashcard retention by 200% over linear review
Retrieval practice twice daily retains 92% of facts after 7 days vs 60% passive
Testing effect doubles long-term retention (76% vs 36%) after 1 week, Roediger study
Self-testing improves retention by 50% over restudying for text material
Sleep after learning consolidates memory, boosting retention by 20-40% next day
90 minutes of sleep post-training retains 85% vs 60% wakefulness, Stickgold study
REM sleep enhances procedural memory retention by 30%
Multimedia learning with images retains 65% vs 45% text-only, Mayer principle
Dual-coding theory: visuals + words retain 89% vs 72% single mode
Elaborative encoding with examples boosts retention 40%

Without review we forget quickly, but spaced repetition locks in knowledge.

Environmental and Methodological Influences

Multimedia learning with images retains 65% vs 45% text-only, Mayer principle
Dual-coding theory: visuals + words retain 89% vs 72% single mode
Elaborative encoding with examples boosts retention 40%
Mnemonics like method of loci retain 70% names after 1 month
Concrete examples in lessons retain 68% vs 39% abstract
Storytelling framing retains 22% more info than facts alone
Gamification with badges increases retention 30% in e-learning
Background music distracts, reducing retention by 15% for verbal tasks
Contextual cues at retrieval match encoding boost retention 50%
Social context encoding retains 35% more with peers present
Scent cues matching study/test retain 15% more
Pomodoro technique (25 min study) retains 28% more than marathon
Feynman technique explaining simply retains 50% deeper understanding
Mind mapping visuals retain 32% more hierarchical info
Interleaved topics retain 76% vs 42% blocked practice
Augmented reality learning retains 75% vs 40% traditional
Peer teaching retains 90% vs 50% passive listening
Error-based learning retains 40% more robust knowledge
Daylight exposure during study boosts retention 20%

Environmental and Methodological Influences Interpretation

While these statistics suggest we might remember 90% of what we teach but only 10% of what we read, the real lesson is that our brains are like eccentric librarians who vastly prefer filing knowledge with a partner, a picture, a story, or even a peculiar smell.

Forgetting Rates

In Ebbinghaus's classic experiment, individuals forget approximately 58% of newly learned nonsense syllables within 20 minutes without review
After one hour, retention drops to about 44% for the same nonsense syllables in Ebbinghaus's study
By the end of 24 hours, only 33% of nonsense syllables are retained without reinforcement, per Ebbinghaus
After 6 days, retention falls to 25% for rote-learned material in Ebbinghaus's curve
One month post-learning, nonsense syllable retention is around 21% without spaced review
Modern replications show 42% forgetting of factual knowledge within 1 day in medical students
70% of lecture content is forgotten within 24 hours by college students
Half-life of knowledge in corporate training is 5 years, leading to 20% annual decay
Surgeons forget 30% of surgical knowledge within 1 year post-training
Language learners forget 50% of vocabulary in 2 weeks without practice
Interference from similar info causes 35% forgetting in paired associates
Retroactive interference reduces retention by 28% post new learning
Emotional arousal slows forgetting by 20% for central details
Hyperthymesia cases retain 99.99% autobiographical events
Alcohol intoxication at encoding causes 40% steeper forgetting curve
Age-related forgetting accelerates: 20% per decade after 30 for episodic memory
Stress hormones like cortisol increase forgetting by 25% short-term
Bilinguals forget L2 words 15% faster than L1 without use
Video game skills decay 10% per week without play
Musical instrument proficiency forgets 30% in 3 months idle
56% of new hires forget training in 1 hour, 88% in 1 week without spacing
Physicians forget 58% of knowledge in first year residency
Software devs forget 80% API docs in 2 days
Consumers forget 90% ad content in 3 days
Students forget 65% class material by exam time
Teams forget project procedures 50% in 6 months
Artists forget techniques 35% after 1 month break

Forgetting Rates Interpretation

The relentless drip of our mental bucket is universal, whether for nonsense syllables or lifesaving procedures, proving that to truly own knowledge we must continuously refill it through review and practice.

Repetition and Spacing

Spaced repetition at 1-day interval boosts retention to 80% after 1 week vs 50% massed
Expanding intervals (1,3,7 days) yield 90% retention after 30 days, per Cepeda study
Leitner system with 5 boxes increases flashcard retention by 200% over linear review
Spacing factor of 2.5 in Anki software retains 95% of items after 1 year
Three spaced sessions over a week retain 65% vs 30% single session after 1 month
Optimal spacing lag of 10-30% of test interval maximizes retention by 40%
Daily micro-sessions of 10 min spaced over month retain 85% vs 55% cramming
Bilingual spacing training retains 75% vocabulary after 6 months
Interleaved practice with spacing boosts math retention by 43% after 1 week
SuperMemo algorithm SM-18 achieves 97% retention with adaptive spacing
Spacing with 1-week gap retains 82% vs 55% immediate for vocab
Hyperbolic spacing (days 1,2,4,8) achieves 93% after 2 months
App-based spacing retains 78% languages after 1 year, Duolingo study
Review at 35% fluency threshold optimizes retention to 96%
Clustered spacing over 3 days retains 70% vs 45% distributed poorly
Long lag spacing (1 month) retains 60% better for durable skills
Mixed modality spacing retains 85% cross-sensory info
Corporate spaced training retains 50% more after 6 months
FSRS algorithm improves Anki retention to 98% long-term
Spacing reduces overconfidence, improving retention accuracy 25%
Spaced reviews every 10 days retain 91% vocab after 1 year
4 spaced exposures needed for 90% retention threshold
Adaptive spacing in RemNote retains 94% user data
Short sessions spaced retain 2x motor skills vs massed

Repetition and Spacing Interpretation

Forgetting may be inevitable, but spaced repetition is the witty, mathematically-backed art of telling your brain “not so fast” at just the right moments, transforming fleeting cramming into lasting mastery.

Sleep and Physiological Factors

Sleep after learning consolidates memory, boosting retention by 20-40% next day
90 minutes of sleep post-training retains 85% vs 60% wakefulness, Stickgold study
REM sleep enhances procedural memory retention by 30%
Napping 60-90 min post-learning improves factual recall by 35%
Sleep spindles correlate with 2x better retention of word pairs
Chronic sleep deprivation reduces retention by 40% in hippocampus-dependent tasks
Daytime naps retain 70% of spatial info vs 50% no nap
Overnight sleep stabilizes memories, reducing forgetting by 25%
Slow-wave sleep boosts declarative memory retention by 50%
Caffeine before sleep impairs retention by 15-20%
Exercise before learning increases retention by 20% via BDNF
Sleep before testing consolidates, boosting recall 22%
Circadian rhythm peaks retention 15% higher morning vs afternoon
Meditation post-learning enhances retention 16% via mindfulness
Hydration levels: Dehydration reduces retention 20%
Omega-3 intake improves retention 25% in elderly
Aerobic exercise post-study retains 30% more episodic memory
Blue light exposure pre-sleep reduces retention 12%
Hormonal cycle: Luteal phase retains 10% more verbal memory
Fasting 16 hours impairs retention 18% short-term
Music during sleep cues retain 20% better targeted memories

Sleep and Physiological Factors Interpretation

If you want your brain to hold onto what you've learned, treat sleep not as a luxury but as a mandatory study session where your memories get organized, and remember, your lifestyle choices from caffeine to exercise are either diligent teaching assistants or mischievous saboteurs in this process.

Testing and Recall

Retrieval practice twice daily retains 92% of facts after 7 days vs 60% passive
Testing effect doubles long-term retention (76% vs 36%) after 1 week, Roediger study
Self-testing improves retention by 50% over restudying for text material
Frequent low-stakes quizzes retain 80% after semester vs 50% no quizzes
Generation effect from recall boosts retention 30% higher than recognition
Distributed practice with tests retains 63% after 3 months vs 28% massed
Flashcard testing with confidence ratings retains 88% after 1 month
Effortful retrieval strengthens memory twice as much as easy recall
Pre-testing before learning boosts final retention by 25%
Repeated testing over 4 sessions retains 90% vs 50% single test
Free recall testing retains 56% vs 40% recognition after delay
Dozens of tests over semester boost retention 2.5x final exam
Elaborative interrogation during tests retains 40% more concepts
Calibration training with tests improves retention judgment 35%
Backward recall chaining retains sequences 50% better
Testing with errors strengthens memory 30% more than correct
Collaborative testing retains 25% more in groups vs solo
Immediate feedback post-test retains 90% vs 70% delayed
High-desirability tests retain emotional content 45% better
Retrieval-induced forgetting protects key memories, retaining 80%

Testing and Recall Interpretation

If you want to make knowledge stick, stop just staring at your notes and start interrogating your memory, because the humble act of self-testing isn't just study advice—it's a forensic tool that forces your brain to stop being lazy and build a lasting case for each fact.

Sources & References

Logos provided by Logo.dev