Henry L. Roediger and Jeff
Karpicke talk with ScienceWatch.com and answer a
few questions about this month's Fast Breaking Paper in the
field of Psychiatry/Psychology.
Article Title: Test-enhanced learning - Taking
memory tests improves long-term retention
Journal: PSYCHOL SCI
Year: MAR 2006
* Washington Univ, Dept Psychol, Campus Box 1125,1
Brookings Dr, St Louis, MO 63130 USA.
* Washington Univ, Dept Psychol, St Louis, MO 63130 USA.
Why do you think your paper is highly cited?
Our paper is probably highly cited for several reasons. First, it shows a
surprising finding (that being tested on material can produce greater gains
in later retention than re-studying the material); second, the research has
educational implications; third, the materials used were more educationally
relevant than is often the case in psychology research on human memory;
fourth, a number of cognitive psychologists have recently become interested
in testing as a means for learning; and fifth, the article was published in
Psychological Science, the most important journal for scientific
psychology, which goes to all 18,000 members of the Association for
Does it describe a new discovery, methodology, or
synthesis of knowledge?
The paper comes closest to describing a new "discovery." The reason for the
quotes around discovery is that, like many phenomena in psychology, the
effects of testing on material relative to studying had been carried out
previously. However, prior work was done almost exclusively with simple
materials like word lists.
Our results extended some earlier findings to prose materials of the sort
that might be used in the classroom. Further, we used repeated tests rather
than single tests as had often been used in prior work and showed that
repeated tests produce larger gains than do single tests.
In addition, we used a procedure of free recall rather than testing for
just bits of information such as in learning used pairs of associated words
(such as foreign language vocabulary). In our study, students were
instructed to recall all they could of each passage when given its title,
which somewhat resemble essay tests in the classroom.
Would you summarize the significance of your paper in
layman s terms?
We had students read prose passages. In our second experiment, they then
either took three tests on the passage (recalling all they could each time)
or they re-read the passage carefully three times for the upcoming test. So
these conditions can be conceived of as SSSS or STTT where S stands for
study and T stands for test.
"We hope to extend
our research in
many directions to
examine benefits of
which are just
of retrieval for
When students took the tests immediately after study, they recalled about
70% of the material. Therefore, students in the repeated study condition
were allowed to restudy the entire passage each time, whereas those in the
repeated test condition studied the whole passage just once and then
recalled what parts they could on three successive tests. We gave a final
criterion test after either five minutes or one week.
The results showed differences depending on when the final test was given.
Briefly, on the test given shortly after the manipulation, the SSSS
students recalled more material than the STTT students. Cramming (repeated,
massed studying) works on a test given immediately after study. However,
any gains from cramming are ephemeral. On a long-term test a week later,
the STTT students recalled much more material than the SSSS students. Our
research shows that taking repeated tests on material leads to better
long-term retention than repeated studying.
How did you become involved in this research, and were
there any problems along the way?
The first author had been involved in studies of repeated testing for many
years (e.g., Roediger & Thorpe, Memory & Cognition, 1978;
Wheeler & Roediger, Psychological Science, 1992). However, in
these prior studies, the use of repeated testing had been to ask questions
other than the memory-related effects of testing per se. When Jeff Karpicke
came to Washington University as a graduate student, we became interested
in the effects of repeated testing in their own right.
One problem is that a huge literature exists on using tests in psychology,
both standardized tests and the use of tests in the laboratory. The
literature dates back over 100 years and sprawls across many journals in
psychology, education, and related fields. We conducted a thorough
literature search simultaneously with our experiments and this was also
published in 2006 (see: "The power of testing: Basic research and
implications for educational practice" in Perspectives on Psychological
Science 1: 181-210).
Where do you see your research leading in the
We hope to extend our research in many directions to examine benefits of
repeated testing, which are just being uncovered (e.g., Karpicke &
Roediger, "The critical importance of retrieval for learning,"
Science 319: 966-968, 2008). We expect that this arena will
continue to be a lively topic of research in psychology, education, and
possibly in cognitive neuroscience, as researchers in the last field
discover the neural underpinnings of the testing effect.
Do you foresee any social or political implications for
We hope that this research may be picked up in educational circles as a way
to improve educational practices, both for students in the classroom and as
a study strategy outside of class.
Students and teachers are generally unaware of the power of testing. In
some contexts, testing has a bad reputation (e.g., an overreliance on
standardized tests, teaching to the test, drill, and practice routines).
However, we believe that intelligent use of testing can greatly facilitate
the process of learning.
Henry L. "Roddy" Roediger III
James S. McDonnell Distinguished University Professor
Chair of the Department of Psychology
Washington University in St. Louis
St. Louis, MO, USA
Jeffrey D. Karpicke
Department of Psychological Sciences
West Lafayette, IN, USA