Tests aren't just a way for teachers to torture their students, according to a new study that finds the brain encodes better mental hints during test-taking than during studying alone。

　　Although many people view tests as a way to mark and grade students' progress, research has found that the act of retrieving information from memory actually makes remembering it easier. In other words, tests improve learning。

　　The study author Mary Pyc, a postdoctoral fellow at Washington University in St. Louis and her co-author Katherine Rawson investigated pieces of information called "mediators." Mediators are concepts, ideas or phrases that connect one piece of information to another. To be a good mediator, the idea has to be both easy to remember and easy to link to the information you're trying to retrieve。

　　To investigate the effect of testing on mediators, Pyc and Rawson had 118 English-speaking participants learn 48 Swahili words. Some of the learners took tests on the information and then got to restudy the material before being tested again. Others only studied and restudied without tests。

　　A week after learning the words, each group took a final test. Some tests required them to give the English translation from the Swahlii word alone. Another group got a test that gave them the Swahili word plus the mediator they'd used when learning the words. A third group not only had to translate the word, but they also had to remember and write down their mediator word。

　　Overall, the group that took practice tests did three times better than the study-only group. In addition, more test practice made for better mediators. Those who had to recall both their mediator and the translation got scores averaging 51 percent if they'd been in the pretesting group and just 34 percent if they'd only studied. Those who didn't have to remember their mediator, just link it to the translation, also did much better if they'd completed practice tests。

　　美国“趣味科学”网站近日报道称，考试不仅仅是老师用来折磨学生的手段，因为最新研究表明，考试时大脑消化吸收学习材料的效果要比只是学习看书时产生的效果好一些。

　　人们把考试视作给学生进步打分的工具，然而研究发现，从记忆中检索信息这一行为可使人们记东西更加容易。换句话说，考试能让你学识渊博。

　　该研究论文的撰稿人、华盛顿大学博士后玛丽-佩克和她的同事凯瑟琳-罗森着手于研究名为“介质”的信息碎片。“介质”实际上就是一些概念、观点或者短语，它们是连接各条信息的桥梁。要成为优质“介质”，相关观点必须易记且和你要检索的信息相关。

　　为了调查考试对“介质”产生的效果，佩克和罗森让118名讲英语人士学习48个斯瓦希里语的单词。在之后的实验中，一部分学习者对所学内容进行测试，然后在再次测试前重新学习。而另一些人则只是学习、再学习，没有测试。

　　一周后，每组都会进行一次期终考试。一组被要求写出斯瓦希里语某些单词的意思，而另一组则在释义时研究者给他们看了自己学习时曾使用的“介质”。第三组不仅需要给单词释义，还要记住并写下自己当时使用的“介质”。

　　总体来讲，经常做测试的那一组的考试结果要比不做测试的那一组好出三倍。此外，测试较多使得学习者使用的“介质”也较好。需要回忆“介质”以及释义的小组成员中，先前在测试较多小组中学习的成员平均分为51分，而那些曾在不测试小组中学习过的成员平均仅为34分。而在考试中不被要求回忆“介质”只需释义的人群，倘若之前做过较多测试，考试成绩也要好得多。