Concern-based cohesion as change proneness indicator: an initial empirical study

Abstract

Structure-based cohesion metrics, such as the well-known Chidamber and Kemerer's Lack of Cohesion in Methods (LCOM), fail to capture the semantic notion of a software component's cohesion. Some researchers claim that it is one of the reasons they are not good indicators of change proneness. The Lack of Concern-based Cohesion metric (LCC) is an alternative cohesion metric which is centered on counting the number of concerns a component implements. A concern is any important concept, feature, property or area of interest of a system that we want to treat in a modular way. In this way, LCC focus on what really matters for assessing a component's cohesion - the amount of responsibilities placed on them. Our aim in this paper is to present an initial investigation about the applicability of this concern-based cohesion metric as a change proneness indicator. We also checked if this metric has a correlation with efferent coupling. An initial empirical assessment work was done with two small to medium-sized systems. Our results indicated a moderate to strong correlation between LCC and change proneness, and also a strong correlation between LCC and efferent coupling.