一节出乎预料的Scratch编程课

编程社区进度快的孩子已经完成第一阶段的学习，掌握了Sequence, Loops, Events, Conditionals, Functions, Variables等基本概念。第二阶段我们会学习block-based的语言Scratch。

我的计划是，让小朋友通过自主完成一系列难度递增的projects来掌握Scratch。第一节课是Animate Your Name, 把自己的名字做成动画。编出的程序应该是类似这样的：

结果一位小朋友对此课程不感兴趣，编了一个自己设计的游戏出来：

这位小朋友直接上手去编自己设计的游戏，遇到问题时再问老师应该用哪些blocks来实现。我们的编程课直接实现了creative computing的目标?！

一开始虽然我很惊讶，但并没有要求小朋友必须做设定的project，而是提供帮助鼓励孩子完成自己的作品。

思考过后，我意识到对于不同的孩子，学习编程的课程内容、方法和进度都是不同的。对于暂时没有idea的孩子，可以按照我们的课程计划稳步学习编程。一旦他们有了自己的想法，就转换为以小朋友为主的学习模式，带着自己的问题来学习编程。学习编程最好的方式就是在真正需要某项功能的时候学习它，这样才能深刻理解这些知识。

最后附上Scratch项目主要负责人Mitch Resnick遇到的一个小故事，也说明了同样的道理。Mitch在编程俱乐部遇到一个正在做大鱼吃小鱼游戏的男孩。这个孩子想用分数记录下多少条小鱼被吃掉了，但是不知道如何实现。Mitch看到这是一个引入variables(变量)概念的好机会，于是给男孩介绍了variables，男孩迅速就掌握了这个概念。男孩对variables有了深入理解，正是因为他真正需要用到它。Mitch认为当孩子们以“meaningful and motivating”的方式来使用编程概念的时候，他们就会对这些概念有更加深刻的理解。

A few years ago I was at one of our Computer Clubhouse after school centers and I saw a 13-year-old boy working on creating his own game. He was able to control a character, in this case, a fish. He wanted the game to keep track of the score, so you could see how many little fish had been eaten by the big fish, but he didn't know how.

I saw this as an opportunity to introduce the idea of variables. I showed this to him and he immediately saw how he could use this block to keep track of how many fish had been eaten in his game. He took the block and put it in the script right where the big fish eats the little fish. He quickly tried it. Sure enough, every time the big fish ate a little fish, the score goes up by 1.

I think that he really got a deep understanding of variables because he really wanted to make use of it. That's one of our overall goals of Scratch. It's not just about variables, but for all types of concepts. We see that kids get a much deeper understanding of the concepts they learn when they are making use of the concepts in a meaningful and motivating way.