Structure is important for algorithms, programs, and data. Structured programming is a philosophy as well as a defined methodology to guide the construction of algorithms and programs. It involves a top-down approach: starting with a given problem, then using stepwise refinement, and breaking problems into smaller component problems that then may be solved independently and subsequently combined. The overall goal is to write programs that are easily understood, debugged, and changed. Data abstraction and functional modularity are important elements of programming style to be incorporated into this approach. Algorithm and program structure have been stressed in this chapter and will continue to be emphasized throughout the book, as will the equally important choice of data structures. The next chapter discusses record and array information and pointers.