Top down design is the act of breaking down a large problem into smaller, easier problems to solve. When writing a program that has a lot of parts, it's good practice to use top down design to break the program into many smaller parts that are easier to solve. It can be good to think about top down design using real world examples. One example you can use is making a movie. Making a movie is a very large problem, but we can break it into problems that are smaller and make it easier to handle. For example, breaking it into parts like: 1. Write the script 2. Film 3. Edit makes it easier to complete, since you can focus your attention on each of those parts separately and solve one smaller problem before moving on. ---------- In Karel, a good example is if you need to write a program where Karel will lay two rows of tennis balls -- one on the bottom row, one on the top row. This is a multi-part problem, so it's easier to solve using top down design. Using that technique, we should try to make methods that do parts of the program that are easier to solve. Let's break down the whole program into. 1. `layRow` 2. `moveToTop` 3. `layRow` As you can see, we now only have 2 smaller problems that we have to solve. It will be easier to approach the `layRow` method and the `moveToTop` method separately and then put them together to make the whole program than to just start coding. Using top down design encourages you to think about your solution and make a plan before you start writing code, so you solve problems in better ways.
