An experiment investigating the effect of information hiding on maintainability

An experiment was conducted to investigate the effects of different levels of information hiding on maintainability. Two versions of an Ada program where created. Each version contained a set of modules with good information hiding and a set with poor information hiding. Subjects were given one of two versions of an Ada program and two modifications to perform. One modification was performed on the well-designed set of modules and one on the poorly-designed set. The results show that sections of the programs with good information hiding do not suffer structural decay as a result of the modification and that sections with poor information hiding are improved in approximately two-thirds of the new versions. These results are especially notable considering that the programmers were, for the most part, unfamiliar with Ada and object-oriented design