Object Oriented Software Understandability An Empirical Investigation

In this paper the results of an empirical investigation into the relationship between software understandability and features of object oriented software are described Five C Systems of varying sizes were analysed and data relating to understandability in heritance coupling and other class features collected for each A number of hypotheses were then investigated to identify relation ships between understandability and proper ties of each system The hypotheses asked whether the extent of class coupling in a sys tem inheritance in a system or class size fea tures methods and attributes a ected the understandability of software Signi cant relationships between understand ability and class coupling were found for three of the systems studied indicating that as cou pling increases understandability decreases Only limited evidence of a relationship be tween understandability and inheritance was found for the ve systems studied suggest ing that inheritance plays a minor role in the assessment of understandability Signi cant positive relationships were found between un derstandability and class size measures indi cating that the number of methods and at tributes in a class strongly in uences under standability The results in this paper highlight the need for more empirical investigations in this area particularly in the understanding of class co hesion and the role of inheritance and cou pling in the assessment of understandability