Indirect Coupling As a Criteria for Modularity

Assessment of a modularisation technique should involve some form of measurement as to how modular the code becomes as a result of applying the technique. One problem we face is that there is a lack of a precise definition of modularity. The IEEE glossary of software engineering terminology defines modularity as "the degree to which a system or computer program is composed of discrete components such that a change to one component has minimal impact on other components. While this is not an operational definition, especially as the notion of discreteness, or independence, needs to be further defined, it provides a good starting point for discussion. To measure according to this definition we need to measure "degree of independence". We are interested in a particular form of dependence, namely indirect dependence and believe this is an important criteria for assessing modularity.