EXAMS:用功學習就一定考出好成績？

用功學習就一定考出好成績？

作者：英國《金融時報》專欄作家提姆•哈福德(Tim Harford)

2007年10月18日 星期四

親愛的經濟學家：

我的經濟學導師說，如果我想在考試中取得好成績，就應該更努力地學習。但我認為，他的建議完全建立在理論假設的基礎上，而沒有實證根據。誰是對的？

讀者：M.W., 劍橋

親愛的M.W.,

你說他的建議不是建立在實證研究基礎上的，這種說法可能是對的：不是因為沒有這方面的研究，而是因為這項研究最近才剛剛公佈。我非常遺憾地告訴你，他的大膽揣測現在已經被一項有趣的自然試驗證實了。

以前的研究人員難以在考試成績和學習時間之間建立一種因果關係。這並不令人驚訝。好學生可能更用功，因為他們喜歡學習。差生可能為了幾個而在考試前突擊學習。解開這些統計數字似乎是不可能的。

但這個謎團被經濟學家陶德•斯坦布裏克納(Todd Stinebrickner)和他的父親、數學家拉爾夫•斯坦布裏克納(Ralph Stinebrickner)解開了 ((HC案：PDF] The Causal Effect of Studying on Academic Performance Todd ...))。

他們給一些學生隨機分配了一位擁有遊戲機的室友，然後借助詳細的時間使用問卷，對這些學生進行了考查。這些學生和他 們的室友在初始測試成績、喝酒或睡眠的時間等方面都沒有差別。但那些室友有視頻遊戲機的學生減少了學習時間，將更多時間花在玩《最終幻想12》(Final Fantasy XII)上。純粹的偶然——分配室友——似乎影響了學習的時間，不涉及其他任何重要決定。是的，這些學生的成績受到了影響。

如果這項分析是正確的，那麼每天多學習1小時就會對考試成績有非常大的影響——足以將一名普通的學生提升到前三分之一。因此，多花點時間學習是一筆理性的投資，除非你知道一些非常好的電腦遊戲。

譯者/何黎

Dear

Economist,

My economics tutor says that I should be studying harder if I want to do well in my exams. I think that he is basing his advice on purely theoretical assumptions, and that there is no empirical evidence for his assertion. Who is right?

M.W., Cambridge

Dear M.W.,

You're probably correct that his advice is not based on empirical research – not because no research exists, but because it is very recent. But I am sorry to report that his wild speculations have now been confirmed by an intriguing natural experiment.

Previous researchers have struggled to establish a causal link between exam results and time spent studying. That is not a surprise. Bright students might work harder because theyenjoy the work. Or failing students might cram to rescue their grades. Untangling the statistics seems impossible.

Yet the puzzle has been resolved by Todd Stinebrickner, an economist, and his father, mathematician Ralph Stinebrickner. Equipped with detailed time-use questionnaires, they looked at students who were randomly assigned a room-mate with a games console. Neither the students nor their room-mates differed in, say, initial test score, time spent boozing, or sleeping. But students whose room-mates had video games spent less time studying and more playing Final Fantasy XII. Pure chance – the assignment of a room- mate – seems to affect time spent studying, and no other important decisions. And yes, the grades suffered.

If the analysis is correct, an extra hour a day studying has a very substantial impact on test scores – enough to lift a typical student into the top third. Unless you know some very good computer games, that is likely to be a rational investment of your time