General Considerations in Using Data General Data Do all variables have the smallest scope possible? Are references to variables close together? Do control structures match the corresponding data structures? Does each variable have one and only one purpose? Is each variable's meaning explicit, avoiding hidden meanings? Are all the variables that have been declared, used? Global Data Are all variables local unless they absolutely need to be global? Do variable names differentiate between local, module, and global data? Are all global variables documented? Is the code free from pseudo-global data, big data structures containing a mishmash of data that's passed to every routine? Are access routines used instead of global data? Are access routines and data organized into modules, rather than lumping all global data and access routines together? Do access routines provide a level of abstraction beyond their underlying data? Are all related access routines at the same level of abstraction?