Temporal Spacing of Learning:

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Temporal Spacing of Learning Can It Help Reduce
Forgetting?
Hal Pashler University of California, San
Diego Dept of Psychology
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Douglas Rohrer, USF
John Wixted, UCSD
Shana Carpenter, UCSD
Nicholas Cepeda, UCSD Univ of Colorado
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Ed Vul, MIT
Michael Mozer, Univ of Colorado Computer Science
Dept.
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Forgetting A Classic Topic in Experimental
Psychology
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Forgetting in K-12 Education

• Educational failure may often reflect forgetting
  as well as
• absence of initial mastery.

• Regression to partial understanding and
• initial misunderstandings (Bob Siegler).

• Summer Vacation Set-backs

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Father Guido Sarduccis 5-Minute College
People who went to college can tell you what
they learned in just 5 minutes. So, at my
college, students learn just the same stuff
all in 5 minutes.
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Our Research Aim
Identify procedures that

• reduce rate of forgetting

• can readily be applied in educational contexts.

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Topics
1. Temporal Distribution of Practice within
Study Sessions
2. Temporal Distribution of Study Sessions
3. Overlearning
4. Form and Timing of Feedback
5. Testing Effects
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Analyzing Temporal Distribution of Study Sessions
Retention Interval (RI)
Inter-study Interval (ISI)
Study Something Once
Study It Again
Test
Time

• Huge Literature showing poor learning with very
  short ISI (spacing effect)

• Scarcely any application in classroom or
  instructional technology

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Why no practical translation if the literature
is so huge?
425 papers
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Spacing Research with Significant Retention
Intervals (gt 1 day)
14 papers (Many with serious methodological
problems)
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(No Transcript)
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10-day Retention Interval Study
Interstudy Interval 0, 1, 2, 4, 7, 14 days
Tasks Swahili-English Vocabulary
Jani?
Horse
Session 1 Study to Criterion 0,1,2,4,7, or 14
days Session 2 Fixed amount of further
study 10 day RI Session 3 Test
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Data from 182 subjects tested for 3 sessions
10-day RI
Facts
Objects
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6-Month Retention Interval
Interstudy Interval 0, 1, 7, 28, 84, or 168 days
Tasks 1. Learn names of little-known objects
?
Coccolith.
2. Learn little-known facts
Who invented snow golf?
Rudyard Kipling.
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Data from 161 subjects tested for 3 sessions
Swahili
10-day RI
6-month RI Facts
6-month RI Object Names
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Lets Plot Performance as a Function of ISI/RI
Ratio
Optimum ISI 10 20 of retention interval?
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Larger Experiment now in Progress

• Web-based Learning of Facts

• Session 1 Train to Criterion

• Session 2 2 Test/Study Repetitions

• Test Recall, then 5-Alternative Recognition

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Recall Data (n 2,000 subjects)
7 days RI
35 days RI
70 days RI
350 days RI
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Recognition Data (n 2,000 subjects)
7 days RI
35 days RI
70 days RI
350 days RI
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Generalizing Beyond Fact Vocabulary Learning

• Large effects of spacing generalize to learning
  novel mathematical problem-solving skill
  (combinatorics) USF

• Pattern-recognition skills may not show similar
  spacing effects www.learnmelanoma.org

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Empirical Conclusions

• Using appropriate inter-study interval can
  produce 100 - 200 improvement in ultimate
  memory

• Too short an ISI is much worse than too long

• Using ISI of about 10-20 of retention interval
  seem to optimize memory over a wide time range

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Tentative Practical Implications

• To determine optimum spacing, you need to know
  how long you want the learner to retain the
  information.

• For most educational goals, 6-mo. delayed
  reviews likely to be very cost-effective
  (Preuss School Study)

• Cumulative finals probably have huge effect on
  what students retain over years.