From the issue dated June 8, 2007
男人早泄吃什么药最好
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"The testing effect cuts against the lay understanding of memory," says Jeffrey D. Karpicke, who recently completed a doctorate at Washington University and will become an assistant professor of psychology at Purdue University this fall. "People usually imagine memory as a storage space, as a space where we put things, as if they were books in a library. But the act of retrieval is not neutral. It affects the system."
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In a long ries of recent studies, Mr. Roediger and his colleagues have examined the testing effect from veral different angles: Is it better to u short-answer quizzes or multiple choice? Is it crucial to give students immediate feedback on their quiz performance? Does quizzing improve students' long-term learning of related material?
Andrew C. Butler, a graduate student at Washington, recently designed an experiment in which students watched videotaped lectures on concutive days about three Impressionist artists: Berthe Morisot, Pierre-Auguste Renoir, and Edgar Degas. (None of the participating students had taken art-history class, so this was unfamiliar territory.) Immediately after each lecture, a computer screen would train the students in one of three ways: by displaying facts from the lecture, which the student
s would simply read; by giving the students a multiple-choice quiz; or by giving them a short-answer quiz.
The students were randomly assigned into various quences, and they all experienced each study method exactly once. For example, a student might e the Renoir lecture on Day 1 and take a short-answer quiz, e the Morisot lecture on Day 2 and simply read the facts, and e the Degas lecture on Day 3 and take a multiple-choice quiz. Another student might e the Morisot lecture on Day 1 and take a quiz, and so on; there were父亲的画面
27 different pathways in all.
A month later, the students were brought back to take a 90-item short-answer test that covered all three artists. This final test included some facts that the students had not reviewed at all. On tho items, the students answered only 20 percent correct, on average. On the items that had been studied through rereading or through multiple-choice quizzes, the students averaged 36 percent correct. And on the items that had been studied through short-answer quizzes, the students averaged 47 percent correct.
For Mr. Butler, the implications are clear: Instructors should take a few minutes to give quizzes, prefe
分手语录
rably in short-answer format, at the beginning or end of each class ssion. "A lot of educators don't make the connection between their teaching tasks and their evaluation tasks," he says.
When given regular quizzes, Mr. Butler says, students are forced to retrieve facts from memory repeatedly, and they develop much deeper fluency in the material. Instructors might consider it a nuisance to construct and grade the quizzes, he says, but it's far wor to allow students to go 12 weeks between hearing a lecture and coughing up facts on a final exam. Students who wait to cram for a final exam rarely retain the material over the long term, even if they perform reasonably well on the final, Mr. Butler says. "The way that we typically do things in education," Mr. Butler says, "ems almost rever-engineered to produce the least possible learning."
Testing Effects
Tightly constructed experiments like Mr. Butler's are one thing. But Mr. Roediger and his colleagues are also looking at the testing effect in real-world classrooms.
A $3-million, five-year grant from the Institute of Education Sciences, an arm of the U.S. Education Department, supports the team's rearch on social-studies and English class at a middle school in Columbia, Ill., not far from St. Louis, and in Psychology 101 class at the University of New Mexi
co at Albuquerque.一千米等于多少厘米
At the middle school, the Washington University rearchers have worked with teachers to identify roughly 30 key facts in each of the students' textbook chapters. For half of tho facts, the students are given daily quizzes, which the students answer using handheld "clicker" devices manufactured by eInstruction Corporation. The devices allow the students to receive instant feedback on their answers. On the final tests at the end of each unit, the students demonstrate significantly better recall of the quizzed facts than the unquizzed facts.
"We've produced a nice testing effect at Columbia Middle School," says Kathleen B. McDermott, an associate professor of psychology at Washington University. "You can e it very clearly in the data. What we want to do next year is to go back and say, Well, of all of the things that we did, what's crucial? What if they don't get that immediate feedback?" she asks. "What if we don't give them a prequiz at the beginning of the unit, to show them what they don't know?" Tweaking the procedure, Ms. McDermott says, should help to illuminate how the testing effect operates.
At New Mexico, Gordon K. Hodge, an associate professor of psychology, is experimenting with the testing effect in his large introductory cours. Every other week, he requires his students to take dai
ly online quizzes on their own time, as homework. The federally financed study will compare his students' end-of-
mester retention of facts from the quizzes with their retention of facts they learned during the nonquiz weeks.
"Several years ago, our dean identified Psychology 101 as a
'killer cour,'" Mr. Hodge says. "Some administrators were very concerned about how many students were failing. But we in the department didn't want to mend the problem by just making things easier. So we started to look for ways to help students improve their learning."
Contrary to the general wisdom of testing-effect rearch, Mr. Hodge's online quizzes are in multiple-choice rather than short-answer format. Creating and scoring short-answer quizzes for such large class would be too difficult and time-consuming for the instructor, says Mark A. McDaniel, a professor of psychology at Washington who is working cloly with Mr. Hodge on the project. "Maybe we're not that far away from the day when computers can score short-answer tests," Mr. McDaniel says, "but we're not there yet."
遥远的救世主读后感
At Washington University, Ms. McDermott gives four-question short-answer quizzes at the end of every meeting of her 300-level cour on human learning and memory. The class tend to be small — around 20 students — so it is easy to give quizzes at every meeting, she says.
"Sometimes colleagues here will ask me about the quizzes," Ms. McDermott says, "and I'll explain to them why I do this. The hard part is standing firm when you announce it at the beginning of the cour, and dealing with the resistance. But students are always going to complain about something in your cour. It might as well be quizzes."
谢赫六法By the end of the mester, Ms. McDermott says, most students have come to appreciate the role the quizzes play in helping them absorb the cour material.
顺境出人才Too Narrow?
Ms. McDermott says she tries to persuade her colleagues that writing and grading daily quizzes is really not so bad. But her colleagues sometimes come back with another objection: Don't the quizzes encourage students to concentrate on narrow, isolated facts, as oppod to the broader concepts and themes at the heart of the cour?
Rearchers still have a good deal to learn about that question, Ms. McDermott says, but they are starting to believe that frequent quizzing actually helps students absorb a broad range of material not directly included in the quizzes. Jason C.K. Chan, a newly minted Ph.D. at Washington who will become an assistant professor of psychology at Iowa State University this fall,
