Increasing Retention without Increasing Study Time

Increasing Retention without Increasing Study Time

Authors: Doug Rohrer (University of South Florida) and Hal Pashler (University of California, San Diego)Published in: Current Directions in Psychological Science, 2007 (Vol. 132, 354-380)

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Abstract

  • Objective: Explore strategies for long-term retention of learned material.

    • Focus on the duration of study sessions and the distribution of study time.

  • Key Findings:

    • Mastery should be achieved before stopping study sessions.

    • Immediate further study is inefficient.

    • The spacing effect's benefits depend on the intervals between study sessions and tests.

Introduction

  • Educational Challenges:

    • Many students struggle with retention despite extensive classroom time.

    • Examples of poor retention include basic math and geography knowledge.

  • Need for Effective Learning Strategies:

    • Importance of defining strategies that promote long-lasting retention.

    • Research includes testing subjects up to a year after study sessions.

Overlearning

  • Definition: Continuing study after achieving error-free performance.

  • Common Practice: Seen in educational settings, especially in mathematics.

  • Effectiveness of Overlearning:

    • Initial studies show short-term benefits but diminishing returns over time.

    • Example: Vocabulary learning showed significant gains at one week but negligible after four weeks.

Implications of Overlearning

  • Efficiency Comparison:

    • Overlearning may not be the best use of study time compared to reviewing older material.

    • Overlearning is beneficial for short-term retention or critical tasks (e.g., emergency procedures).

Spacing of Learning

  • Concept: Distribution of study time across sessions enhances retention.

  • Research Findings:

    • Spacing is superior to massed study sessions.

    • Optimal inter-session intervals (ISI) vary based on retention intervals (RI).

Varying the Inter-Session Interval

  • Experiments:

    • Studied Swahili-English word pairs with varying ISIs (5 minutes to 14 days).

    • Found that a 1-day ISI yielded the best recall after a 10-day RI.

    • For obscure object names, a 1-month ISI was optimal after a 6-month RI.

Interaction of ISI and RI

  • Findings:

    • Optimal ISI increases with longer RIs.

    • Performance declines with increased RI, but optimal ISI improves retention.

Mathematics Learning

  • Research on Overlearning and Spacing:

    • Overlearning did not significantly improve test scores in mathematics.

    • Spacing practice problems across sessions led to better retention than massing similar problems.

Recommendations for Mathematics Textbooks

  • Current Format Issues:

    • Textbooks often promote massing and overlearning.

  • Proposed Format:

    • Shuffle practice problems to enhance spacing and variety, improving learning outcomes.

The Bigger Picture

  • Other Learning Decisions:

    • Importance of self-testing versus re-studying answers.

    • Retrieval practice is generally more effective.

  • Future Directions:

    • Need for empirical research to inform educational practices.

    • Potential for educational software to optimize study schedules for better retention.

Recommended Readings

  • A selection of studies and reviews that support the findings and implications discussed in the manuscript.

References

  • A comprehensive list of studies and literature cited throughout the manuscript, providing a foundation for the research and

Abstract

The primary objective of this research is to identify pedagogical strategies that enhance the long-term retention of learned material without increasing the net study time. The researchers, Rohrer and Pashler, focus on the distinction between the quantity of study and the timing of study. Their findings indicate that while initial mastery is necessary, the common practice of overlearning (immediate further study) provides diminishing returns. Success in long-term memory is instead driven by the spacing effect, which involves distributing study sessions over time based on the intended Retention Interval (RI).

Introduction

A significant challenge in modern education is the rapid rate of forgetting. Students often lack basic knowledge in geography, mathematics, and history within even a few years of instruction. To combat this, cognitive psychologists look for "time-efficient" strategies that ensure knowledge lasts. Research methodologies in this field have evolved to test subjects over extended periods, sometimes up to 11 year, to accurately measure the durability of memory.

Overlearning

Definition: Overlearning is the process of continuing to practice or study a task after the learner has achieved a criterion of one error-free performance.

  • Educational Ubiquity: This is a standard method in classrooms; for example, a student might solve 2020 variations of the same math problem even after they have grasped the formula.

  • Effectiveness Analysis:

    • Short-term: Overlearning provides a clear advantage if the test occurs immediately or within a few days.

    • Long-term: Research on vocabulary retention shows that while overlearners perform better after 11 week, there is virtually no difference in performance after 44 weeks compared to those who stopped once they achieved mastery.

  • Efficiency Recommendation: Overlearning is only advisable for critical tasks requiring absolute perfection under stress (e.g., emergency medical procedures). For general academic learning, it is an inefficient use of time.

Spacing of Learning (Distributed Practice)

The Spacing Effect suggests that separating study sessions by a specific timeframe (the Inter-Session Interval or ISI) significantly improves recall compared to "massed" practice (cramming).

The ISI and RI Relationship

Experiments varying the interval between the first and second study sessions revealed that the optimal ISI depends on when the information needs to be recalled (the Retention Interval):

  • Experimental Data: For a test occurring in 1010 days, a 11-day gap between study sessions was superior. For a test in 66 months, a gap of approximately 11 month was most effective.

  • Heuristic: To maximize performance, the ISI should generally be roughly 10%10% to 20%20% of the RI. If the RI is very short (e.g., minutes), the ISI should be short. If the RI is long (e.g., years), the ISI must be measured in months.

Mathematics Learning

Math education is particularly prone to the pitfalls of massed practice and overlearning. Typical textbooks provide a lesson followed by many problems on that specific topic.

  • Proposed Reform: Textbooks should move toward interleaving or shuffling practice problems. Instead of 1010 problems on topic A followed by 1010 on topic B, problems from topics A, B, and C should be mixed.

  • Benefits: This forces students to practice selecting the correct strategy for each problem type, which is exactly what a final exam requires. Spaced math practice has consistently shown to double retention scores compared to massed practice.

The Bigger Picture: Retrieval Practice

Beyond timing, the nature of the study session matters:

  • Testing Effect: Actively retrieving information from memory (e.g., flashcards or practice tests) creates stronger memory traces than passive re-reading.

  • Strategic Software: There is a growing call for educational software that uses algorithms to track student performance and automatically calculate the optimal ISI for each concept, ensuring that review occurs at the moment of maximum benefit.

Recommended Readings and References

  • Rohrer & Taylor (2006): Discussion on the effects of overlearning and distributed practice in mathematics.

  • Cepeda et al. (2006): A meta-analysis of the spacing effect and the mathematical relationship between ISI and RI.