The Globe and Mail

At the start of term, Karl Szpunar’s students sigh or groan when he tells them there will be a quiz at the end of every class. Two or three usually drop his course.

By the final exam, though, many of them are grateful. The Harvard University researcher quizzes his students to boost their memories, an approach based on compelling scientific evidence that shows the value of testing as a learning tool. Over the past decade, study after study has found students who are quizzed on new material recall significantly more of it compared with students who aren’t. This holds true for science, history, languages and many other subjects. The experiments also show that taking a test is more effective than an extra hour or so of study.

Most have involved undergraduates and were done in laboratories, but now researchers are moving into the hurly-burly of Grade 6, 7 and 8 classrooms and getting impressive results. Dr. Szpunar, a Canadian who studies memory, is probing the brain mechanisms involved. He is on the forefront of a nascent discipline of neuro-education, a field that could challenge conventional notions about how we learn. The work on testing is promising but not without controversy; the researchers say they face resistance from teachers who equate it with standardized testing, a flashpoint in schools across the continent. Some critics fret that extra tests will help students regurgitate information but not understand it.

In an effort to gain widespread acceptance of their work, researchers are delving deeper into the “testing effect,” or as some scientists now prefer to call it, the “retrieval effect.”

What is it about retrieving information, whether in a pop quiz, flashcards or even a classroom game of Jeopardy, that is so effective at creating long-term memories? Why is it better than rereading a chapter or reviewing notes?

There are a number of theories. Some involve the chemical or physical changes that occur in the brain when we summon a memory and reprocess it. Dr. Szpunar and his colleague have found evidence the testing helps protect against what scientists call “proactive interference,” something most of us have experienced when we feel overwhelmed by too much information.

It happens when you’ve been studying for an hour and feel that you can no longer take anything else in. The amount of material you absorbed in the first half hour makes it hard to digest what you read in the second half, says Dr. Szpunar. In one experiment, he found that students, asked to learn five lists of words, did significantly better on the fifth list if they were tested after each one. He is doing a postdoctoral fellowship at Harvard and is hoping to use brain imaging to learn more.

Others are moving into the classroom. Henry Roediger and his colleagues at Washington University in St. Louis recently reported the results of a study with a Grade 8 science class. The students learned about genetics, astronomy, chemistry and anatomy, but were quizzed on only half of the material. That testing was low-stakes; it didn’t count much toward their mark.

But it made a big difference. They scored 13- to 25 per cent higher on the parts of the final exam they had been previously quizzed on, a jump from a C-plus to an A-minus, says Pooja Agarwal, a member of the research team. Same students, same teacher; the difference was in the quizzing.

She and her colleagues stress that quizzes are only one of many tools that effective teachers use, including good instruction, demonstrations and active, hands-on learning. But they can make a significant difference in how well students perform.

But will quizzes improve their understanding of a topic? Or will they simply be better at reciting facts?