For effective teaching ，subject matter knowledge is not a question of being a walking encyclopedia.Effective teachers not only know their subjects,but they can also communicate their knowledge to students.The celebrated high school math teacher Jaime Escalante taught the concept of positive and negative numbers to students in a Los Angeles barrio by explaining that when you dig a hole,you might call the pile of dirt +1驾霜，the hole-1.What do you get when you put the dirt back in the hole?Zero.Escalante's ability to relate the abstract concept of positive and negative numbers to his ?students ' experience is one example of how the ability to communicate knowledge goes far beyond simply konwing the facts.
為了有效的教隶债，學(xué)科知識不是一個行走的百科全書式的問題秦忿。
效率高的教師，不僅自己知道學(xué)科知識，而且還能把知識傳遞給把知識傳遞給學(xué)生。
一所著名中學(xué)的數(shù)學(xué)老師在教授正負數(shù)概念的時候演顾，他是這樣解釋的，當(dāng)他挖挖一個洞的時候隅居，他把挖出的一部分成為正一钠至，這個洞稱為負一。
那么把土放回去的時候會發(fā)生什么呢军浆？零棕洋。他的把抽象的正負數(shù)概念和學(xué)生的經(jīng)歷聯(lián)系起來的能力是一個很好的實例，用來說明想學(xué)生傳遞知識的能力比知識本身重要乒融。
