1. Don Slater dslater@andrew.cmu.edu Wanda Dann wpdann@andrew.cmu.edu Copyright 2012 Wanda Dann, Don Slater All rights reserved

2. Do in order penguin swagger penguin pushes the bowling ball so it rolls to the pin pin falls over pin responds (stands up and pushes the ball back to penguin) penguin falls over  Algorithm  Initial Scene

3. Where are we? Problem Statement Understand the problem Implement the design Test the code Design a solution

4.  Implementation is the act of translating an algorithm/storyboard into a computer program.  To Translate  Decompose algorithm step by step  Incrementally develop and test program statements

5. Step 3: Implement the design  Decompose Problem Statement Understand the problem Implement the design Test the code Design a solution Develop a storyboard / algorithm Decompose into simple steps

6.  Break an action into simpler steps 12/17/09 Do in order penguin swagger penguin pushes the bowling ball so it rolls to the pin pin falls over pin responds (stands up and pushes the ball back to penguin) penguin falls over penguin move forward penguin roll left penguin roll right penguin stand up straight

7. Incremental Development  Write code Write statements (code) – a few steps at a time, not the entire program at once! Problem Statement Understand the problem Implement the design Test the code Design a solution Decompose into simple steps

8.  A statement is created by dragging a code tile into the edit space

9. Actions useful for setup Same actions and more  Scene Editor  Code Editor

10. Step 5: Test and Revise, if needed Problem Statement Understand the problem Revise? Implement Revise? Test the code Design a solution Revise? Does it work, no matter what? Try different values (distance, direction, revs)

11.  When Run… button is clicked ◦ Alice builds the scene for the runtime window ◦ Executes the program statements, starting with the myFirstMethod procedure (defined in MyScene) Runtime window

12.  However…..  Where is the swagger? Do in order penguin swagger penguin pushes the bowling ball so it rolls to the pin pin falls over pin responds (stands up and pushes the ball back to penguin) penguin falls over

13.  Creating our own procedures - or -  Teaching a penguin to swagger