Keynote discusses the science behind successful learning

Quizzes and tests can be a powerful tool for learning, according to Dr. Henry L. “Roddy” Roediger, the keynote speaker for the 9th annual Celebrate Learning Week. His keynote, “Making it Stick: The Science of Successful Learning”, looked at the impact of frequent quizzing on learning and memory.

A common assumption in education is that learning happens during studying, and tests simply measure this learning, noted Roediger, who is the James S. McDonnell Distinguished University Professor of Psychology at Washington University. He believes this is ultimately an ineffective approach to learning.

“One of the best ways to learn is to quiz yourself, to test yourself…either in the classroom or at home,” he said. This method, known as retrieval practice, or the testing effect, “enhances long-term retention and slows forgetting.” He shared several studies that illustrate its impact.

Word Recall1

In one experiment, students studied a list of 50 words and were asked to recall as many words as they remembered. Students were placed in one of three conditions:

  • Study four times, and take four tests
  • Study six times, and take two tests
  • Study eight times

All students took a final test two days later. The results showed that students in the third condition, who studied the most, only recalled 17% of the words. Students in the first condition, who had the least time to study but took the most tests, recalled 39% of the words.

The Dropout Method2

Roediger pointed to a common study strategy called the drop-out process, where once you have studied and are able to recall an item, you drop that item from further studying and testing. In another experiment, students studied 40 words and took a final test a week later to see how many words they remembered. There were two conditions:

  • Standard: Study all 40 words, then take a test. Repeat eight times.
  • Dropout: Study all 40 words and recall as many as possible. Drop the recalled words and study the remaining words for a total of eight cycles.

During the process of learning, it appeared the dropout method worked better—students got 100% of the words with the dropout method, but only 85% with the standard method.

However, during the final test a week later, students in the standard condition recalled twice as many words as the dropout method. Roediger attributed this to a term called desirable difficulties, which “slows learning initially but makes long-term performance better.”

Passage Recall3

To test students on more complex material, Roediger conducted a study where students read and were asked to recall a 250-word passage under one of three conditions:

  • Study the passage (on average, students read the passage 14 times)
  • Study the passage and take one test (on average, students read the passage 10 times)
  • Study the passage and take three tests (on average, students read the passage 3.5 times)

When surveyed, students who studied the most thought they would remember the most, and students who studied the least, but were tested the most, thought they would do the worst. The results of the final test showed differently.

Roediger explained, “The students that had been tested, even though they found the test hard…they didn’t think they were doing that well…they did the best. The group that was the most confident they would do well the following week did the worst.”

He pointed to a concept known as the illusion of mastery. “When you read something over and over, you really feel like you’ve got it…but until you test yourself on it, until you’re quizzed, until you can show you can use the knowledge, how do you know you know it? You’ve got to be able to use that knowledge, not just be able to take it in and passively read.”

A new way of teaching

Roediger stated that, among the benefits of retrieval practice, it identifies gaps in knowledge and directs future study, helps organize knowledge, and reduces test anxiety.

Following his studies, Roediger has changed the way he teaches. He now asks students to hand in or complete some form of low stakes assignment, such as quizzes, every class. Roediger also advocated for active learning and suggested posing problems or questions where students have to apply what they learned.

Roediger’s keynote was part of Celebrate Learning Week, an annual week-long showcase of teaching and learning opportunities at UBC. A full recording of his keynote is available online.


  • Zaromb, F. M., & Roediger, H. L. (2010). The testing effect in free recall is associated with enhanced organizational processes. Memory & Cognition, 38, 995-1008. – begins at 15:34 in recording
  • Karpicke, J. D., & Roediger, H. L. (2007). Repeated retrieval during learning is the key to long-term retention. Journal of Memory and Language, 57, 151-162. – – begins at 23:20 in recording
  • Roediger, H. L., & Karpicke, J.D. (2006). The power of testing memory: Basic research and implications for educational practice. Perspectives on Psychological Science, 1, 181-210. – begins at 34:19 in recording